WO1993019633A1

WO1993019633A1 - Shoe last

Info

Publication number: WO1993019633A1
Application number: PCT/US1993/003042
Authority: WO
Inventors: Jerry F. Gumbert
Original assignee: Gumbert Jerry F
Priority date: 1992-04-01
Filing date: 1993-03-31
Publication date: 1993-10-14
Also published as: CA2132973A1; AU3943293A

Abstract

An improved shoe-making last (5) comprising a three-dimensional last structure having no last bottom featherline (24) around the periphery of the last sole surface (10) and having intersecting lateral (32) and longitudinal (30) curved arches on the sole surface (10) of the last, and further having a toe section (60) that maintains generally a uniform thickness along its length and humps (70, 72) on the last upper surface above the heal seat of the last to simulate the ankle bones of a human. The shoe-making last being dimensioned to account for the dynamic shape of the human foot to provide footwear which is more stable, more comfortable and physiologically more correct than footwear made with conventional lasts.

Description

SHOE LAST

RELATED APPLICATIONS

This application is a continuation-in-part of my application, Serial

No. 07/861,460, filed April 1, 1992, and entitled "Shoe Last".

FIELD OF THE INVENTION This invention relates to a shoe-making last for manufacturing footwear. More specifically, this invention relates to a last which is physiologically closer to the natural shape of a human foot than are conventional shoe-making lasts.

BACKGROUND OF THE INVENTION A shoe-making last is the solid, three-dimensional mold over which footwear is made. The last is firmly mounted, and the pieces of shoe material, whether upper or sole material, are placed around the last and attached together to make the shoe. The last shape largely determines the shape of the shoe and how it fits and feels on the wearer's foot. Consequently, the shape of the shoe-making last is critical in order to make footwear which fits comfortably on the foot, provides adequate support and performs essentially as an extension of the human foot, as is desired. Conventional shoe-making lasts and the footwear manufactured using these conventional lasts have fallen short of the goal of providing footwear which works in harmony with the human foot. All currently available shoe- making lasts have a flat sole surface which meets the upper last surface at approximately a 90° angle. The corner of the angle creates what is referred to as a last bottom featherline which extends around the periphery of the bottom of the last. When a last having a flat sole surface and a sharp angled featherline is utilized to make a shoe, a stiff, flat sole piece must be placed on the flat bottom of the last and attached to the upper piece or pieces of the shoe. The flat sole surface and angled featherline are significant drawbacks of conventional lasts because the resulting footwear has rigid soles which underlie the foot so as to artificially support the foot on a stiff platform. Since the stiff platform is flat, it does not conform to the natural curves and arches of the bottom of the human foot, and, as a result, causes foot discomfort. Additionally, the human foot in motion has a tendency to want to fall off the end of the stiff sole platform of the shoe thus increasing the risks of ankle injuries.

To offset some of the effects of the stiff platform on the human foot, shoe manufacturers must artificially reinforce the underside of the wearer's foot by placing a mass of material on the inside of the shoe to coincide with and

bolster the foot's natural arches. However, as can be appreciated, the natural human foot neither has nor requires what is commonly referred to as "arch support." The unnatural stiff support and arch reinforcement in shoes made using conventional shoe-making lasts therefore result in a disharmony between the foot and the shoe which produces, among other things, foot discomfort, back pain and an increased risk of injury.

Conventional shoe-making lasts, in addition to having a flat sole surface and a rigid featherline where the sole meets the last upper surface, also have a heel section or heel "seat" which is elevated vertically above the ball and toe section of the last when the ball and toe section is substantially horizontal.

The elevated heel seat of conventional lasts makes it necessary to attach solid heels to the resulting footwear to make it function properly. A woman's shoe with spike heels is illustrative. The elevated heel seat further makes the conventional lasts different from the natural foot, because feet do not have elevated heels. Additionally, in shoes made using conventional lasts, the risks of ankle injury are increased with the necessary addition of a heel to the stiff sole platform, because the foot in motion will now have a tendency to roll off of an elevated sole platform. Conventional shoe-making lasts have a front toe section which tapers to a point both in from the sides and top to bottom from the base to the tip of the toe section. The toe profile or "toe recede", as it is called, of conventional lasts is angled along the length of the toe section from the base of the toe section to the tip to create an abrupt 90° angled featherline at the tip of the last toe section. Human toes are not tapered or shaped this way, but rather they maintain a generally uniform thickness from the base to the tip of the toe and then gradually taper at the end of the toe. Consequently, footwear manufactured using conventional lasts pinches the toes in sideways and from top to bottom, causing

further foot discomfort. The tapered toe section of conventional lasts also results in a confinement of the foot at the points most necessary for propulsion, that is, the ball and toe region of the flat foot. Additionally, conventional lasts are essentially flat in the upper surface above the heel seat and do not conform to the curves of the foot associated with the human ankle bones. Summarizing, conventional shoe-making lasts do not provide footwear which is anatomically in harmony with the natural human foot. The shoes made from conventional lasts support the foot on an artificial elevated stiff platform, require excess material to shore up the natural arches of the foot because it is supported on a stiff platform, bind the foot at the toe and ball region and generally restrict the foot in motion and at rest.

It is therefore an objective to provide a shoe-making last which, is physiologically more in harmony with the natural shape of the human foot than are conventional lasts. It is a further objective to provide a last which can be used to manufacture footwear that operates as an extension of the human foot rather than confining and supporting the foot unnaturally. It is a still further objective of the invention to take into account the dynamic shape of a foot in motion. SUMMARY OF THE INVENTION

In accordance with these objectives, the shoe making last of the present invention has a shape which is generally more consistent with the shape of a natural human foot than are conventional lasts. The upper surface of the last connects to the bottom sole surface of the last in a continuous curve, wherein there is no sharp angled featherline around the periphery of the sole section of the last. Extending from essentially the ball area of the last sole surface to the heel seat of the sole surface is a longitudinal arch which rises smoothly from the plane of the ball area of the sole upward to its highest elevation and then smoothly back down again to the heel seat of the sole surface. The ball area and heel seat of the sole surface are essentially in the same plane, i.e., the heel seat is not elevated above the ball area as with conventional lasts. A lateral arch extends widthwise across the last and increases in height to a maximum height on the inner side or instep side of the last. The lateral arch intersects with the longitudinal arch, and as the lateral arch increases in height from side-to-side across the width of the last sole surface, the longitudinal arch also increases to reach its maximum height also at the inner side of the last. The coordination of the intersecting longitudinal and lateral arches on the last simulates the inward arch of the human foot. Furthermore, the combination of the smooth transition between the last upper surface and the bottom sole surface, and the longitudinal and lateral arches creates a last sole surface which is physiologically in harmony with the natural bottom surface of the human foot.

The front section of the last, or toe section, is generally free from toe recede and maintains a generally uniform thickness from the base of the toe section to the tip of the toe section which gradually decreases down to the toe tip. The last does not taper down to a sharp abrupt featherline at the front tip of the last as do the toe sections of conventional lasts. The last does taper in thickness, however, from the inner side of the last to the outer side of the last at the toe section to simulate the size differential between the thickness of the big toe and the thickness of the smallest toe. Similarly, the length of the toe section of the last gradually tapers to a shorter length from the inner side of the last to the outer side to reflect varying toe length unlike conventional lasts which unnaturally have a dramatic width taper at the toe section of the last. Due to the lack of a last bottom featherline, the upper surface of the last in the toe region joins with the sole surface in a smooth, continuous curve. In the upper part of the last, above the heel seat, and on either side of the last, are two projecting ankle bone humps which mimic the medial and lateral malleoli, or ankle bones, of the human foot. In this way, the footwear made from the last of the present invention conforms to fit around the ankle bones of the wearer. While the last of the present invention is inherently longer in length than the foot length reference or foot size to which the last corresponds, one embodiment of the last is dimensioned in length to reflect an increase of approximately 3-10% over the foot length reference to which the last corresponds. This percentage increase in last length yields a last length reference used to form the last which takes into account the dynamic length increases of a human foot in motion.

In accordance with another aspect of the present invention, an

embodiment of the last also reflects a last circumference reference as measured approximately around the ball of the foot which is greater than the circumference reference of the foot to which the last corresponds. Preferably, the increase in last circumference around the ball area of the last is approximately 1-6% over the foot circumference reference measurement of the corresponding foot.

In accordance with still further aspects of the present invention, the

last instep reference measurement and last heel opening reference measurement on the last of an embodiment of this present invention reflect increases over the foot instep reference and foot heel opening measurements of the foot to which the last corresponds. As a result of these dimensional increases in the last, the shoe last even further reflects the dimensional changes in the dynamic foot so that footwear made from such a last fits the foot more comfortably and is more stable than footwear made with conventional lasts.

The present invention thus offers a unique, non-conventional, shoe- making last which has a shape more in harmony with the natural foot than do conventional lasts. The unconventional lack of a flat sole surface on the last and the lack of a distinct featherline separating the sole surface from the upper surface allows the manufacturing of footwear which does not require a stiff platform for artificially elevating and supporting the foot. Without a stiff support platform, shoes made from the last of the present invention do not require an artificial support mass underneath the instep of the wearer's foot to offset the effects of the stiff sole. The ball area and the heel seat of the last of the present invention lie in the same plane, and consequently, footwear created from the last of the present invention does not require an artificial heel for attachment to the bottom of the shoe in order to maintain proper functioning of the shoe. The lateral and longitudinal arches of the last invention cause the last to generally conform to the natural curves of the human foot so as to make footwear manufactured therewith more of an extension of the foot than are those produced using conventional shoe- making lasts. Furthermore, the increased reference dimensions of the last over the associated dimensions of the foot to which the last corresponds results in

production of footwear which accounts for the dynamic shape of the foot and which does not constrict the foot while it is at rest or in motion, thus allowing the foot to maintain its natural shape during all forms of weight bearing. As a result, the footwear manufactured using the last of the present invention is more comfortable, more stable, and functions more efficiently as an extension of the human foot than footwear produced using conventional shoe-making last.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects of the invention are more fully understood with reference to the following description of a preferred embodiment taken in conjunction with the accompanying drawings in which: Fig. 1 is a bottom perspective view of the shoe-making last in accordance with the principles of the present invention;

Fig. 2 is a top perspective view of the shoe-making last in accordance with the principles of the present invention;

Fig. 3 is a side view of the shoe-making last in accordance with the principles of the present invention;

Fig. 4 is a front view of the shoe-making last in accordance with the principles of the present invention;

Fig. 5 is a top view of a shoe-making last in accordance with the principles of the present invention; Fig. 6 is a side view of a traditional shoe-making last; and

Fig. 7 is a bottom view of a traditional shoe-making last. DETAILED DESCRIPTION

Referring to Figures 1 and 2, the shoe-making last 5 of the present

invention has a shape generally of a human foot. Last 5 has a bottom sole surface 10 having a heel seat 12 and a ball area 14, and an upper surface 16 which joins sole surface 10 in a continuous curve 18 presenting a last which is free from the angled last bottom featherline existent on all conventional shoe-making lasts. As illustrated with reference to Figs. 5 and 6, all conventional lasts 19 have an upper surfaee 20 and a flat, bottom surface 22 which meets upper surface 20 at a 90° angle to form a rigid, angled featherline 24 around the periphery of sole surface

22. However, everywhere on last 5 of the present invention upper surface 16

meets sole surface 10 in a continuous, smooth curve 18 with no rigid featherline, so that upper surface 16 smoothly connects with sole surface 10 around the entire periphery of last 5 (see Fig. 5.).

Referring again to Fig. 2, the absence of a flat sole surface 22 and distinct last bottom featherline 24 on last 5 allows the last of the present invention to be used to manufacture footwear which does not require a stiff sole platform at the bottom of the shoe, as is necessary with conventional last 19 (Fig. 6). The inside bottom of a shoe (not shown) manufactured using last 5 of the present

invention conforms to the natural meeting of the top of the human foot to the bottom sole surface. This presents footwear more comfortable to the human wearer than traditional shoes, because the inside bottom of a shoe manufactured using last 5 works in harmony with rather than against the human foot as do the flat, rigid shoe soles necessary when using a conventional last.

Referring now to Fig. 3, the ball area 14 of last 5 lies in a plane and the heel seat 12 lies in substantially the same plane, i.e., there is no heel elevation in the last of the present invention. As illustrated in Fig. 6, conventional lasts have heel seats 25 which are in a plane vertically elevated above the plane of the ball area 27 of the conventional last. The resulting heel elevation

26 of the 19 requires a stiff heel to be added to the bottom of traditional footwear to support the heel of the wearer and to make the footwear function properly.

The lack of heel elevation in last 5 of the present invention eliminates the need to have a stiff heel placed beneath the sole of the resulting footwear to make the footwear function properly. The freedom from heel elevation 26, present in conventional shoe-making lasts, provides a last 5 that is further in harmony with the natural shape of a human foot than are conventional lasts. Additionally, the stiff, heel-elevated, sole platform that is necessary with the use of conventional lasts causes ankle and foot injuries and exacerbates existent injuries, because the human foot in motion has a tendency to roll or fall off of the stiff platform which may be elevated an inch or more above the ground because of the heel. However, using last 5 of the present invention, there is no stiff, elevated sole platform beneath the foot, and the moving foot has a tendency to roll inwardly or outwardly like the bare human foot reducing the many foot and ankle injuries caused by stiff, elevated soles.

Turning now to Fig. 3, last 5 has a smooth longitudinal arch 30 which extends lengthwise on the sole surface 10 of last 5 from approximately forward of heel seat 12 to approximately rearward of ball area 14, and a lateral

arch 32 which extends widthwise across the last from the outer side 34 to the inner side 36 of last 5 (See Fig. 2). The combination of longitudinal and lateral arches, 30 and 32, present a sole surface 10 which is physiologically more in harmony with the bottom surface of a natural human foot. Conventional lasts (See Figs. 6 and 7) do not have curved arches on their sole surfaces and as a result footwear manufactured with conventional lasts does not conform to the bottom contours of the human foot. Consequently, in conventional footwear there is a gap between the foot of the wearer and the flat sole platform on which the foot is supported, which is not present in footwear manufactured using the last of the present invention.

As best illustrated in Figs. 1 and 3, the lateral arch 32 and longitudinal arch 30 intersect on sole surface 10 of last 5. The lateral arch 32 rises as it extends from the outer side 34 to the inner side 36 of last 5 to reach its maximum vertical height 39 at point 31 at the inner side 36 of last 5. The longitudinal arch 30 extends lengthwise on the sole surface 10 to span between heel seat 12 and ball area 14. Longitudinal arch 30, because of its intersection with lateral arch 32, also increases in height as the lateral arch 32 increases in height. Consequently, the longitudinal arch 30 has its lowest vertical height 38 at the outer side 34 of last 5 and its highest vertical height 39 at the inner side 36 of last 5 as indicated by point 31. Therefore, both the longitudinal arch 30 and lateral arch 32 reach their maximum vertical height 39 at point 31 at the inner side 36 of last 5. The combination of intersecting arches, 30 and 32, and the simultaneous rise in height traversing across the width of sole surface 10 simulates the natural in-step arch of a human foot and as a result presents a sole surface 10 even more closely in harmony with a natural human foot than the sole surface of a conventional last. In accordance with the principles of the present invention, the

maximum vertical height 39 of the arches, 30 and 32, has a dimension of

approximately 10 to 15% of the total length of the last 42 from the heel end 44 to

the toe end 45. The maximum height 39 at point 31 is measured at a distance 43 from the heel end 44 which is approximately 1/3 the total length or "stick length"

42 of last 5. While lateral arch 32 rises from outer side 34 to its maximum height

39 and then smoothly merges to meet upper surface 16 of last 5, longitudinal arch

30 rises smoothly from the plane of heel seat 12 upward to a maximum height (which height depends on its point of intersection with lateral arch 32) and then smoothly back down again to ball area 14 of last 5.

The stiff, flat sole platform which is necessary in footwear manufactured using conventional lasts, when placed against a human foot, results in a gap between the foot and the platform due to the natural in-step arch of the foot. To compensate for this gap in footwear manufactured using conventional lasts, a mass of material is usually placed between the sole platform and the inside of the foot. This mass is placed therein under the pretense of giving arch support to the foot. However, the natural human foot neither has nor needs arch support. Therefore, the combination of arch support and a stiff sole platform results in a disharmony between the human foot and footwear manufactured using conventional lasts. On the other hand, footwear manufactured using last 5 of the present invention, due to the combination of the longitudinal and lateral arches 30

and 32, respectively, has a bottom sole surface 10 which generally conforms to the natural in-step arch of the human foot. The conforming sole surface 10 eliminates the necessity of placing an artificial mass of material above the sole of the shoe to reinforce and bolster the foot's natural in-step arch.

Referring again to Fig. 3, last 5 has a toe section 60 which extends from approximately the forward end 62 of longitudinal arch 30 to the toe end 45 of last 5. As shown in the side profile of Fig. 3, toe section 60 maintains generally a uniform thickness over its length from one end 62 to the tip of 45 of last 5, but gradually diminishes down to the tip 45 of last 5. In reference to shoe- making lasts, the term "toe recede" is defined as the slope of the upper surface 16 of the last from the toe point 45 to the point of full toe thickness, which is proximate point 62 on last 5. On conventional lasts, as illustrated in Figs. 5 and 6, the last 19 has a very definite toe recede as indicated by line 69 and angle θ. Conventional last 19 tapers from upper surface 20 to meet the flat sole surface 22 at a 90" angle to create the angled featherline 24 at the toe end 64 of last 19. Furthermore, conventional last 19 also radically tapers inward from opposing sides, 65 and 66, to point 67 at the front of last 19. As may be appreciated, human toes do not taper radically from the sides to a definite point nor do they taper from top to bottom along their length to form a sharp, angled featherline. Rather, human toes maintain a generally uniform thickness from the base to the tip of the toe (with slight undulations along their length) and they gradually taper to the tip of the toe. Therefore, last 5 of the present invention is responsive to the natural thickness of the human toes where conventional lasts 19 are not.

At the tip 45 of toe section 60 and all around the front of last 5, sole surface 10, proximate to ball area 14 is connected to upper surface 16 by a smooth curve 68. Therefore, the last 5 is substantially free from conventional toe recede and has no distinct featherline at the toe end 45 of last 5 as is present in conventional lasts 19 (see Fig. 6). Referring now to Fig. 4, last 5 gradually tapers in thickness when moving from inner side 36 to outer side 34 in the direction of arrow 49. This side-to-side taper reflects the decreased thickness of

the toes from the big toe to the smallest toe on the human foot. For example, while generally uniform thickness is maintained in toe section 60 longitudinally in the direction of arrow 47 from base 62 to tip 45, the thickness gradually tapers from inner side 36 to outer side 34 in the direction of arrow 49. Therefore, the smallest toe thickness of toe section 60 on last 5 is proximate to outer side 34 while the greatest toe thickness of toe section 60 is proximate to inner side 36 (see

Fig. 4). However, even proximate to the outer side 34, the thickness of the last in toe section 60 along the direction of arrow 47 will be generally uniform.

Additionally, as may be seen in Fig. 5, the length of toe section 60 gradually decreases on last 5 moving from inner side 36 to outer side in the direction of arrow 49. This gradual decrease in the length of last 5 simulates the natural length difference on the human foot between the big toe and the smallest toe. Therefore, last 5 of the present invention more closely resembles the natural shape of in the human foot, and consequently, shoes made from the last 5 of the present invention do not constrict the foot at the toe and ball regions and cause foot discomfort as does footwear made with conventional lasts.

The physiology of the human foot, both statically (when the foot is at rest), and dynamically (when the foot is moving), has been studied. The

physical functioning of the foot is discussed in applicant's patents, U.S. Patent Nos. 4,619,058 and 4,942,678 which are incorporated herein by reference. While

the above described shoe last discloses a last which is longer and wider than the predetermined foot for which the last would be used to make a shoe, in accordance with the principles of the present invention, it has been empirically determined that the dimensions of the last should be increased by specific amounts

over the size of the foot for which the last is used in order to more closely mimic the natural spread and dimensional increase of the foot structure while the foot is static and while it is dynamic. In other words, a last which is used to make a shoe for a defined foot size, is made by dimensioning the last such that it is larger than the defined foot by certain empirically determined amounts. In this way, the last 5 of the present invention has both a contoured sole surface 10 and dimensions which more closely mimic the dynamic physiological shape of the foot.

When designing a last to build a shoe, a measure of foot length is defined as a reference and is assigned a foot size number. For example, column 1 of Table 1 below assigns a particular foot size number to a measurement of foot length to yield a foot length reference which is used to make the last. Table 1 is one example of a series of foot length references and associated foot size numbers which might be used in the last industry when designing lasts for making shoes to fit a particular size foot. A shoe-making last is formed and dimensioned using a chosen foot length reference so that a shoe manufactured using the last fits a foot which has a length that is approximately the same as the predetermined foot length reference. Since a foot size number has been associated with each foot length

reference used to make the last 5, the last 5 yields a shoe which may be referred to by the foot size number of the last as opposed to its actual length. The foot size number is what consumers generally use when purchasing shoes to fit their feet. Table 1 below illustrates one example of the foot size number-to-foot length reference relationship: Table 1:

SELECTED HUMAN FOOT LENGTH REFERENCES AND POSSIBLE 5 CORRESPONDING FOOT SIZE NUMBERS

Foot Length Foot Size Reference

Number (Inches)

10

0 7-1/4 + 1/32

15

2 7-15/16"

3 8-1/4 + 1/32

20

4 8-5/8

5 8-15/16

25 6 9-1/4 + 1/32

7 9-5/8

8 9-15/16 30

9 10-1/4 + 1/32

10 10-5/8 35 11 10-15/16

12 11-1/4 + 1/32

40

15 12-1/4 + 1/32

45 As seen in Table 1, a foot size number of 7 has been assigned to correspond to the foot length reference of 9% inches. Therefore, a last assigned a foot size no. 7, would theoretically produce a shoe which fits a human foot which is approximately 9% inches in length. In turn, the shoe made from a size 7 last will be designated as a size no. 7. Half sizes will generally correspond to a foot length reference which falls between the foot length references given in Table 1.

It may be appreciated that different styles of shoes may fit differently, and therefore, a consumer that fits into a shoe of one size of a particular style may not fit into that same size in a shoe of a different style. It may also be appreciated that the assigned foot size numbers are relative and for reference only and may be shifted upwardly and downwardly such as by making a

foot size 9, instead of foot size 7, correspond to a foot length reference of 9-5/8 inches. The reference lengths and size numbers shown in the chart above are utilized by some footwear manufacturers. There are numerous other reference scales that exist for assigning a size to a particular human foot length; some metric, some English, some unique unto themselves. All, however, can be translated or converted to correspond closely with Table 1. The reference point

for all of the reference scales is an accurate measurement of the length of the human foot. Traditional lasts often yield shoes that restrict the foot because among other reasons, they utilize a static foot length reference without recognizing

the dynamic components of the foot. The shoe last 5 of the present invention takes into account the dynamic factors of the foot during such motions as walking and running. Through studies of the human body, the applicant has empirically determined various dimensions of the human foot which increase during motion.

The last of the present invention reflects these dimensional changes to yield a shoe last which conforms to the dynamic physiological structure of the foot more precisely than those conventional lasts, which do not take into account the dynamic dimensional increases nor have contoured surfaces and a sole surface free of a last bottom featherline.

Through studies of the human foot in motion, the applicant has empirically determined that a last must be increased to be longer than the predetermined foot length reference by approximately 3-10%. A last 5 increased by such an amount over a particular foot length reference produces a shoe which fits a human foot having a length approximately the same as the foot length reference, and thus yields a shoe which may be referred to with the predetermined foot size number assigned to that foot length reference. However, unlike a conventional last, last 5, dimensioned as such yields shoes which take into account the dynamic shape of the foot. For example, referring again to foot size no. 7, in

Table 1, the corresponding foot length reference of 9-5/8 inches is increased to yield a last length reference which is approximately 9.91 to 10.59 inches. This last length reference is utilized to make last 5. For each successive foot size number and corresponding foot length reference, the last length reference of the present invention is found by adding 3-10% to the foot length reference. The actual increase of the last length references will depend upon the style of shoe to be made with the last.

Table 2 below shows a series of foot size numbers with

corresponding foot size references and one set of associated last length references which were generated in accordance with the principles of the present invention.

Column 4 of Table 2 indicates the specific percentage increase of the foot length reference which would yield the associated last length reference of last 5 as show in col. 3. As seen in column 4 of Table 2, as the assigned foot size number increases, the corresponding last length reference reflects a decreasing percentage length increase over the foot length reference. For example, a foot size number 2 designates a foot length reference of 7-15/16 inches and a corresponding last length reference of 8-35/64 inches which corresponds to an increase over the foot size reference of approximately 7.68%. Foot size number 15 and the associated foot length reference of 12-1/4 + 1/32 inches corresponds to a last length reference of 12-57/64 inches which corresponds to an increase of 4.96% over the foot length reference. However, this is not necessarily always the case as the increasing sizes may correspond to graduated increases of the foot size reference so that the percentage increase remains fairly constant or increases. Table 2 only gives one example of length increases.

Table 2:

EXAMPLE TABLE OF POSSIBLE LAST LENGTHS FOR VARIOUS FOOT SIZE REFERENCES

Foot Size Last Size

Reference Reference Size (Inches) (Inches) %

7-15/16 8-35/64 7.68

5 8-15/16 9-35/64 6.82

6 9-1/4 + 1/32 9-57/64 6.57

7 9-5/8 10-15/64 6.33

8 9-15/16 10-35/64 6.13 9 10-1/4 + 1/32 10-57/64 5.93

10 10-5/8 11-15/64 5.74

11 10-15/16 11-35/64 5.57

12 11-1/4 + 1/32 11-57/64 5.40

15 12-1/4 + 1/13 12-57/64 4.96

Therefore, in accordance with the principles of the present

invention, the length 42 of last 5, which is referred to as the stick length, is increased to be longer than the predetermined foot length reference to which the last corresponds. A shoe produced from a last made using the last length reference is made to fit a human foot which has a length approximately the same as the initial foot length reference. The increase in the length of the last as indicated by the last length reference incorporates the dynamic lengthening of the foot during motion and, therefore, provides a last 5 which corresponds to a human foot better than traditional lasts. As seen from Table 2, the increase of the foot length reference yields a last length reference that is generally between 3 and 10% above the length of comparable foot sizes. However, the actual percentage increase of the foot length reference to yield a last length reference may be varied by a person of ordinary skill in the art to yield a last length reference outside of the preferred percentage ranges without departing from the scope of the present invention.

Referring to Fig. 5, the stick length 42 of last 5 is measured from the end point 45 of the toe section 60 to the end point 44 at the heel end of last 5. In accordance with the principles of the present invention, the increase in last length from the predetermined foot length reference is not made only in the toe section 60 so as to yield a longer toe section 60, but rather, the last 5 is increased along the entire stick length 42 of last 5. It has been physiologically determined that when a foot increases in length due to weightbearing and motion, the longitudinal arch of the foot generally moves both forward and backward as it is depressed downwardly from above. Therefore, when increasing last 5 from a foot

length reference in order to yield a last length reference for the present invention, the increase in length is made both forwardly of the last 5 in the toe section 60 and rearwardly in the heel seat 12 in the direction of heel end 44, and generally equally in both directions from approximately point 31. In accordance with another aspect of the present invention, the last

5 takes into account other dimensional changes in the dynamic human foot. The foot, in addition to increasing in length during motion, also increases in circumference around the heads of the metatarsals. The heads of the metatarsals are proximate to the ball region of the foot. It has been determined that increasing the circumference measurement around the heads of the metatarsals, that is, increasing the foot circumference reference, yields a last circumference reference that will result in a last that produces a more comfortable and more physiologically correct shoe. Referring to Figs. 1 and 2, line 73 in the ball area 14 of last 5 indicates where the last circumference is measured. The last circumference measured around line 73 in the ball area 14 of last 5 reflects the increased last circumference reference that is greater than the foot circumference measurement of the reference foot. It has further been determined that an increase of approximately 1-6% of the foot circumference reference yields a last that effectively reflects the dimensional changes of the foot. Although, it should be understood that the range of increase is a preferred range and that a last increased by a greater or lesser percentage may still yield a sufficient last in accordance

with the principles of the invention. Therefore, beginning with the circumference around the heads of the metatarsals of the reference foot for which the last is intended, a last circumference reference for last 5 is preferably established by increasing the foot circumference reference by approximately 1-6%.

In one embodiment of the foot last 5 of the present invention, the last circumference reference is increased 1/4 inch for each increase in foot size

number of the last. (See col. 1 of Table 1.) For example, the last circumference reference is increased 1/4 of an inch when the associated last length reference is increased from last size number 8 to last size number 9. Of course, the exact percentage increase of the foot circumference reference to yield the last circumference may be varied. Therefore, the combination of a last which is increased in length and circumference in comparison to the foot size to which it corresponds in accompaniment with lack of the last bottom featherline on the last

5 yields a last which produces footwear that is more comfortable and more stable, and functions more efficiently on the human foot than footwear using conventional shoe-making lasts. In accordance with another aspect of the present invention, last 5 may have a heel opening which is greater than the foot heel opening of the corresponding reference foot. Referring again to Fig. 3, the last heel opening is designated as the circumference measurement around line 74 which extends around last 5 from a point 75 on upper surface 16 to a point 76 proximate the heel seat 12 and the proximate point 44 of the heel. To establish a foot heel opening reference, a measurement is made around the reference foot at similar points. It has been determined that increasing the foot heel opening reference measurement

by up to 6% to generate a last heel opening reference to form a last 5, further enhances the operation of last 5 to yield more physiologically correct footwear. Again, the percentage range of increase is a preferred range, and a last heel opening reference that is greater than 6% may produce a last sufficient for a

particular type shoe.

It has further been determined that increasing the instep

measurement of the reference foot to generate a last instep reference and using that last instep reference to form a last further enhances the operation of last 5.

The last instep reference is reflected on last 5 by line 77 which extends around last 5 between point 78 proximate point 75 and the point 31 which is located on the sole surface 10 at the maximum height 39 of longitudinal arch 32 on the instq) side 36 of last 5. Preferably, an increase of up to 2% of the foot instep measurement to yield a last instep reference will result in a last which produces shoes which are more comfortable on the feet.

In accordance with still an additional feature of the last 5 of the present invention, ankle bone humps 70 and 72 (see Fig. 4) are formed on the upper surface 16 of last 5 above and slightly forward of heel seat 12. These humps, 70 and 72, simulate the medial (inward) and lateral (outward) malleoli, or ankle bones, of the human foot, and result in footwear which conforms to the ankle bones of the human foot.

While the present invention has been illustrated by the description of various embodiments, and while those embodiments have been described in considerable detail, it is not the intention of applicant to limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, differing sizing scales and reference dimensions may be used when making the last of the present invention. The invention in its broader aspect is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of applicant's general inventive concept. I claim:

Claims

1. A method of making a shoe last to be used in the production of shoes comprising: a.) providing a measurement of foot length to define a foot length reference; b.) increasing the predetermined foot length reference to generate a last length reference; c.) forming a solid last with sides, a toe portion, a heel portion,

an upper surface and a sole surface to have a length dimension which reflects the last length reference; d.) contouring the sole surface and upper surface of the last to reflect structural components of the human foot so that the last from the upper surface to the sole surface presents a continuous curve free from a last bottom featherline.

2. The method of claim 1 wherein the foot length reference is increased by approximately 3 to 10 percent to generate the last length reference.

3. The method of claim 1 further comprising: a.) forming the sole surface of the last to have a ball area which lies in a plane and a heel seat which lies in generally the same plane so that the ball area and heel seat are generally co-planar.

4. The method of claim 3 further comprising: a.) defining a first point on the sole surface of the last, the first point being located a first distance from an endmost point of the heel portion wherein the first distance is approximately 1/3 the last length dimension; and b.) contouring a smooth longitudinal arch to extend a lengthwise on the sole surface of the last, the longitudinal arch having a maximum vertical rise from plane of the heel portion which is approximately 10 to 15% of the last length dimension.

5. The method of claim 1 further comprising: a.) contouring a smooth lateral arch to extend from side-to-side on the sole surface of the last.

6. The method of claim 1 further comprising: a.) forming internal and external ankle bone humps in the upper surface of the last generally above the heel portion.

7. The method of claim 1 wherein the toe portion includes a toe section with a base and a tip, the method further comprising: a.) forming the toe section to have generally uniform thickness from the base to the tip whereby the toe section is substantially free from toe

recede.

8. The method of claim 1 further comprising: a.) providing a measurement of foot circumference to define a foot circumference reference; b.) increasing the foot circumference reference to generate a last

circumference reference; and c.) forming the last such that the circumference distance measured around the last proximate to the toe portion of the last reflects the last circumference reference.

9. The method of claim 8 wherein the foot circumference reference is increased by approximately 1 to 6 percent.

10. The method of claim 1 further comprising: a.) providing a measurement of a foot instep to define a foot instep reference;

b.) increasing the foot instep reference to generate a last instep reference; and c.) forming the last such that the instep distance measured around the last reflects the last instep reference.

11. The method of claim 10 wherein the foot instep reference is increased by up to 2 percent.

12. The method of claim 1 further comprising: a.) providing a measurement of a foot heel opening to define a foot heel opening reference; b.) increasing the foot heel opening reference up to 6 percent to generate a last heel opening reference; and c.) forming the last such that the distance measured around the heel opening reflects the last foot heel opening reference.

13. The method of claim 12 wherein the foot heel opening reference is increased up to 6 percent.

14. A method of making a shoe last to be used in the production of shoes comprising: a.) providing a measurement of foot length to define a foot length reference; b.) increasing the predetermined foot length reference by approximately 3 to 10 percent to generate a last length reference; c.) forming a solid last with sides, a toe portion, a heel portion, an upper surface and a sole surface to have a length dimension which reflects the last length reference; d.) contouring the sole surface and upper surface of the last to reflect structural components of the human foot so that the last from the upper surface to the sole surface presents a continuous curve free from a last bottom featherline; e.) defining a first point on the sole surface of the last, the first point being located a first distance from an endmost point of the heel portion wherein the first distance is approximately 1/3 the last length dimension; and f.) contouring a smooth longitudinal arch to extend lengthwise on the sole surface of the last, the sole surface of the last heel portion being essentially planar, and the longitudinal arch having a maximum vertical rise from

the plane of the heel portion which is approximately 10-15% the last length dimension.

15. The method of claim 14 further comprising: a.) contouring a smooth lateral arch to extend from side-to-side on the sole surface of the last.

16. The method of claim 14 further comprising: a.) forming the sole surface of the last to have a ball area which lies in a plane and a heel seat which lies in generally the same plane so that the ball area and heel seat are generally co-planar.

17. The method of claim 14 further comprising: a.) providing a measurement of foot circumference to define a foot circumference reference; b.) increasing the foot circumference reference by approximately 1 to 6 percent to generate a last circumference reference; and c.) forming the last such that the circumference distance measured around the last proximate to the toe portion of the last reflects the last circumference reference.

18. The method of claim 14 wherein the toe portion includes a toe

section with a base and a tip, the method further comprising: a.) forming the toe section to have generally uniform thickness from the base to the tip whereby the toe section is substantially free from toe recede.

19. A last for constructing a shoe of a selected reference foot size, the last comprising a body dimensioned longer than the dimensional length of the corresponding reference foot for which the shoe is intended, the last further comprising: opposing sides, a toe portion, a heel portion, an upper surface and a sole surface, the sole surface of the last being connected to the upper surface by a continuous curve so that the last is free from the last bottom featherline.

20. The last of claim 19 wherein the body is dimensioned longer in length than the corresponding reference foot by an amount that is approximately 3- 10% of the length of the corresponding foot.

21. The last of claim 19 the sole surface of the last having a ball area lying in a plane and a heel seat lying generally in the same plane whereby the ball area and heel seat are generally co-planar.

22. The last of claim 21 further including a smooth longitudinal arch formed on the sole surface to extend lengthwise thereon, the arch having a first

point defined thereon and located a distance from the endmost point on the heel portion, wherein the distance is approximately 1/3 the last length dimension, the longitudinal arch having a maximum vertical rise from the plane of the heel

portion which is approximately 10-15% of the last length dimension.

23. The last of claim 19 further including a smooth lateral arch formed on the sole surface of the last to extend from side-to-side on the sole surface in a continuous curve from one side of the sole surface to the other side.

24. The last of claim 19 further including internal and external ankle bone humps formed in the upper surface of the last to oppose each other generally above the heel portion to simulate the natural ankle bone shapes of the human foot.

25. The last of claim 19 wherein the toe portion includes a toe section, the toe section having a base and a tip and having generally uniform thickness from the base to the tip whereby the toe section is substantially free from toe recede.

26. The last of claim 19 wherein the last has a circumference that is greater than the foot circumference of the reference foot.

27. The last of claim 26 wherein the last is greater in circumference by approximately 1 to 6 percent.

28. The last of claim 19 wherein the last has an instep measurement that

is greater than the foot instep measurement of the reference foot.

29. The last of claim 28 wherein the last instep measurement is greater by up to 2 percent.

30. The last of claim 19 wherein the last has a heel opening greater than the foot heel opening of the reference foot.

31. The last of claim 19 wherein the last heel opening is greater by up to 6 percent.