WO1996028059A9

WO1996028059A9 - Last for an article of footwear and footwear made therefrom

Info

Publication number: WO1996028059A9
Application number: PCT/US1996/003160
Authority: WO
Filing date: 1996-03-08
Publication date: 1996-11-28

Abstract

An improved last (10), and article of footwear (24) derived therefrom, for providing improved function, fit, and comfort for use in various athletic activities, and in particular for running. The last (10) has dimensions defined by a plurality of cross-sectional contours (12) extending from proximate a proximal end of the heel portion (14) to proximate a distal end of the forefoot portion (16). The last (10) dimensions are in accordance with or proportional to the plurality of cross-sectional contours shown in Figs. 13-106. The last (10) is characterized by a natural shape to the top of the cone (30) or island and an enlarged toe box.

Description

LAST FOR AN ARTICLE OF FOOTWEAR AND FOOTWEAR MADE THEREFROM

TECHNICAL FIELD

The present invention is directed to a last for manufacturing an article of footwear, an article of footwear that is made therefrom and, in particular, to a last suitable for making articles of footwear specifically designed for a particular athletic activity, such as hiking, outdoor activities, running, basketball, and die like. BACKGROUND OF THE INVENTION

A last serves to substantially define the internal and external shape, as well as die overall geometry, of an article of footwear. Accordingly, die fit, function, and comfort of an article of footwear greatiy depends upon die last from which it is derived. The last represents die footwear manufacturer's solution to die problem of finding a generic prescription for optimally accommodating die anatomical characteristics of a broad segment of die general public. The last is tiierefore an essential tool in die manufacture of an article of footwear and a well designed last is an extremely valuable commercial asset to a footwear manufacturer.

A last is the foot-shaped form or model over which an article of footwear is formed. A prior art last generally includes four main parts: die last block, a metal plate covering a portion or all of die sole area, a hinge in die middle of die last which allows tiie last to be divided for easy removal of the last from the shoe, and a thimble tiirough die top and backpart of die last which allows a spindle to be inserted to hold tiie last during die shoemaking process.

Some of die common measurements which are taken into consideration when making a last are shown in FIGS. 1-4. As illustrated, die cone "c" for prior art last "L" is die upper portion extending from die ball portion to d e top of die heel portion. The upper surface or top of die last is referred to as die cone island "ci". The last may also have an elevation of die toe tip tiiat is measured from d e tread point "tp" and a toe tiiickness "til" which defines die space given for die toes of die wearer of the footwear. The elevation of die toe tip is called toe spring "t" . The ball or ball girth "b" of die last is die greatest dimension around die forefoot area of die last. The bottom of tiie last extends upwardly from the tread point "tp" to define die heel height "h". The short heel or short heel girth "sh" of die last is die dimension around a last passing tiirough die instep and the heel feathering point. The instep or instep girth "i" is die dimension around die last passing tiirough die instep point. Similarly, the waist or waist girth "w" is die smallest dimension around die last between die ball girth and the instep girth. As shown in Fig. 2, two common measurements for a last are die stick lengtii "si" and die

SUBSTITUTE SHEET (RULE 2 bottom lengtii "bl" which are taken by a measuring instrument called a stick. Further terms of art and measurements known to one of ordinary skill in die art are described in American Lastmaking, by Karl C. Adrian, published in 1991 by me Shoe Trades Publishing Company, of Arlington, Massachusetts, die entire contents of which are hereby incorporated by reference.

Ideally, an article of footwear made on a last should guide die foot in a

natural walking or running posture for optimum distribution of supportive and

propulsive forces during each step. The article of footwear made on die last should also provide maximum comfort and freedom from excessive stress on d e muscles, ligaments and tendons of die foot and leg. In prior art lasts, however, tiiese objectives have not always been met. For example, die narrow cone shape present in many prior art lasts may produce an uncomfortable ankle region in die finished article of footwear. Further, die molding techniques and measurements utilized for making many lasts in the prior art generally do not take into consideration die curvature of die bottom of die foot, die first toe length and die weight which is borne by die finished article of footwear. SUMMARY OF THE INVENTION

The preferred embodiment of tiie present invention provides a last for making an article of footwear. The last includes a forefoot portion, a cone portion rearward of die forefoot portion, and a heel portion rearward of the cone portion. The last has dimensions in accordance witii or proportional to tiiose of Figs. 13- 106. More particularly, die last dimensions are further defined by a plurality of cross-sectional contours extending from a proximal end of die heel portion to a distal end of die forefoot portion. The cross-sectional contours are taken along consecutive parallel planes to a reference X-Y plane defined as Z being equal to 0.0. The cross-sectional contours are derived from ninety-four cross sections taken tiirough die last, a first cross section being located at or a short distance from die proximal end of die heel portion and a ninety-fourth cross section being located at or a short distance from me distal end of tiie forefoot portion, witii die short distances being generally less tiian or equal to the spacing between adjacent cross sections, and each cross-sectional contour corresponding to each respective cross section tiirough d e last.

Thus, die present invention overcomes die disadvantages of die prior art by providing a last having a more natural shape cone area. This natural shape is complimentary to the ankle region of a wearer and tims produces a comfortable fit for e article of footwear. In addition, die present invention provides a widened and taller toe box area in order to provide greater space for die first toe or hallux. Further, since die molds for developing the last of the present invention are taken in a weight bearing condition, die article of footwear tiius produced better conforms to the foot during the weight bearing phase of walking and running.

The preferred embodiment of an article of footwear according to the present invention has a shape complimentary to at of die inventive last. BRIEF DESCRIPTION OF THE DRAWINGS

The above description and other objects, advantages, and features of die present invention will be more fully understood and appreciated by reference to die specification and accompanying drawings, wherein: Figure 1 is a side view representation of a prior art last showing tiie approximate location of die short heel, instep, waist and ball last measurements;

Figure 2 is a side view representation of a prior art last showing bottom length and stick length last measurements;

Figure 3 is a side view representation of a prior art last showing heel height, tread point, and toe spring last measurements;

Figure 4 is a top view of a prior art last showing die top of the cone or island, cone and front cone areas;

Figure 5 is a perspective view of a computer generated tiiree dimensional representation of a last according to me preferred embodiment of the present invention;

Figure 6 is a rear view of die last representation of Figure 5;

Figure 7 is a side schematic of die last representation of Figure 5 indicating die cross sections 1-94 taken dierethrough;

Figure 8 is a bottom schematic of tiie last representation of Figure 5 indicting die cross sections 1-94 taken dieredirough;

Figure 9 is a top view of die last representation of Figure 5;

Figure 10 graphically shows die stick length, toe spring, ball, waist, heel height, and short heel measurements of the last of die present invention as graded for sizes 6 tiirough 15;

Figures 11(a) and (b) are top and front views of an article of footwear for a left foot of a wearer made on die last according to d e present invention; Figures 12(a), (b) and (c) illustrate templates for final finishing of the toe, heel and bottom portions of die last according to die present invention; and

Figures 13-106 are cross sectional contours of die last shown in Fig. 5 as taken along parallel lines 1 to 94 as shown in Figures 7 and 8. IWTAH-ED DF^SCRIPTION OF THE PREFERRED EMBODIMENTS

The last 10 in accordance witii die present invention is shown by tiie computer generated tiiree dimensional representation of Fig. 5. This view is taken on die lateral side of last 10 looking downward at an angle of approximately 45 degrees relative to die respective orientations of die X, Y, and Z axes. Last 10 is preferably utilized in die manufacture of an article of footwear used for hiking. Referring also to Figs. 6-8, a plurality of cross-sectional contours 12 are numbered as sections 1-1 to 94-94 and extend from proximate die rearmost portion or proximal end of die heel 14 to proximate the anteriormost portion or distal end of die toe 16. Proximate in accordance witii die present invention implies a spaced interval of 0mm to 3mm. In a preferred embodiment, contours 12 are also evenly spaced at 3mm intervals, derived from consecutive and parallel transverse planes corresponding to die X-Y plane. Thus, die first cross section is taken approximately 3mm or less from die proximal end of die heel 14 and die last cross section is taken approximately 3mm or less from the distal end of die toe 16. Cross-sectional contours 1-1 to 94-94 are graphically illustrated in Figs. 13-106. Last 10 as shown is used for making articles of footwear for the right foot. It is within die ordinary knowledge of one skilled in the art to reverse die orientation of die specified contours 1-1 to 94-94 in order to form a symmetric last for making articles of footwear for die left foot. Thus, it can be readily understood tiiat die last of die present invention for die preferred model size shown is defined by die contours of Figs. 13-106.

Figs. 7 and 8 illustrate die last 10 representation of Fig. 1 in side and bottom views, respectively, to more clearly show cross-sectional contours 12 extending from proximate die rearmost portion of die heel 14 to proximate die

anteriormost portion of the toe 16 of die inventive last 10. The cross section lines

1-1 to 94-94 are evenly spaced at 3mm intervals, in die preferred embodiment in order to provide sufficient contour definitions for forming last 10. Otiier spacing intervals, could also be used, however, to derive die overall shape of last 10. Cross-sectional contours 12, and in particular, die parallel X-Y plane defined by cross section 1-1 preferably begins equal to or less tiian 3mm anterior to a point which delimits the rearmost portion of die heel 14 of tiie last 10. Each succeeding parallel X-Y plane, defined by cross sections 2-2 tiirough 94-94, is evenly spaced 3mm apart, and extends consecutively to a position proximate the anteriormost portion of die toe 16 of die last 10.

Figures 13-106 represent die cross-sectional contours 12 tiiat are derived from cross section 1-1 through 94-94. The orientation of each of die cross- sections is shown witii reference to die X and Y axes as die section line is extended along die Z-plane in 3mm increments. It can be readily understood tiiat die shape of each cross-sectional contour 12 shown in Figs. 13-106 represents the intersection between consecutive transverse planes parallel to die X-Y reference and die surface 26 of last 10. The X-Y reference plane is defined when Z = 0.0. More specifically, a heel portion 28 of last 10 is dimensioned generally in accordance witii die cross-sectional contours 1-1 tiirough 38-38 as illustrated in Figs. 13-50. The cone portion 30 of last 10 is dimensioned generally in accordance witii die cross-sectional contours 39-39 tiirough 66-66 as illustrated in Figs. 51-78. Similarly, die forefoot portion 32 is dimensioned generally in accordance witii die cross-sectional contours 67-67 tiirough 94-94 as illustrated in Figs. 79-106.

Referring to Fig. 9, a top view of die last 10 showing die cone portion 30, die top of die cone or cone island 20 disposed at an upper surface of die heel portion 28, and die front cone area 22. A distinctive feature of last 10 of die present invention is its naturally shaped cone island 20 and front cone area 22, as compared witii prior art lasts, such as shown in Fig. 4. This contributes to the article of footwear 24 shown in Fig. 11 having an improved fit and comfort level perceived by die user. Changes could of course be made to die height of die cone 18, i.e., the point along the Y axis at which die last is terminated to form the top of die cone or cone island 20 witiiout departing from the essential teachings of the present invention. In this regard, die height of cone 18 could be changed to facilitate die manufacture of middle or high top articles of footwear. As further shown in Fig. 9, the forefoot portion 32 of last 10 includes an enlarged toe box area in order to comfortably accommodate die first toe or hallux. Further improved comfort and fit is obtained in article of footwear 24, as shown in Figs. 11(a) and (b), by preferably including a lacing system extending along die lateral side of die shoe upper. While advantageous, articles of footwear made from last 10 need not incorporate tiiis closure feature.

The model of last 10 illustrated for die present invention is sized for a men's size 9D hiking or outdoor shoe. Therefore, in order to fabricate lasts for other sizes, die dimensions of last 10 must be graded accordingly. Referring to Fig. 10, die table gives die stick lengtii, toe spring, ball or ball girth, waist or

waist girth, heel height, and short heel measurements of die last 10 of the present

invention as graded for men's sizes 6 through 15 based upon die size 9 model. Common grading of a size 9 men's last is generally consistent with a 1/6 inch or 4.23mm change per one half size in the length dimension, and 1/8 inch or 3.175 change per one half size in die girth dimension, as well as in die ball and waist dimensions.

Utilizing Figs. 13-106, corresponding to cross-sectional contours 1-1 to 94- 94 tiius obtained for die last 10 of die present invention, one skilled in die art can duplicate last 10 through die use of conventional computer assisted design software capable of scanning Figs. 13-106. For example, a computer-aided-design (CAD) module 801 is a three-dimensional graphics software program for generating an geometrical model definition. Such a geometrical model definition includes coordinate points precisely locating the object design in a tiiree-dimensional coordinate system. This may be provided by a graphics software package using, for example, X, Y, and Z coordinate points and appropriate locating vectors where necessary. The tiiree-dimensional graphics software package utilizes appropriate

data structures for defining particular points in the data base of die graphics program. By utilizing algorithms in the graphics program, other points in the object can be defined and generated. The graphics program preferably utilizes appropriate vector and matrix routines whereby an object can be rotated or otherwise moved in computer memory and can be dimensioned whereby the coordinates for any one point are known with respect to other points. As noted above, suitable CAD software packages include I-DEAS (available from SDRC, Inc. of Milford, Ohio), CATIA (available from IBM), and ANVIL-5000 (available from Manufacturing Consulting Services). Alternatively, last 10 of die present invention may be duplicated by manually or mechanically forming shaped components corresponding in dimension to each of die cross-sectional contours shown in Figs. 13-106, and by then aligning die shaped components in die proper orientation and die correct spacing of 3mm and forming a molded surface around die shaped components. Due to die limitations of mathematics, CAD systems, and manual manipulation, tiiere is generally a relatively small amount of variation or uncertainty obtained regarding d e information for die distance between die rearmost portion of die heel 14 and die first cross section 1-1, such distance being generally less tiian or equal to 3mm, and in die distance from die last cross section 94-94 to die anteriormost portion of die toe 16, such distance also being generally less than or equal to 3mm. Accordingly, tiiese portions of die last may be shaped by hand utilizing the templates 34, 36, 38 shown in Fig. 12 for final shaping of die bottom, toe and heel, respectively, of die model men's size 9 shoe. Although unnecessary for making last 10 in accordance witii die present invention, the methodology used to initially fabricate last 10 and tiiereafter generate tiie cross-sectional contours of Figs. 13-106 is described as follows.

The last 10 of die present invention was created by casting in a plaster die feet of a number of subjects during weight bearing, such as would occur when one is hiking. The casts were tiien scanned or digitized into three dimensions using a scanner. The data was then filtered, orientated and averaged using appropriate

software. The data was tiien used to drive a computer numerically controlled (CNC) milling machine and tiius, a prototype last was created. Articles of footwear were made from tiiis prototype last and were tiien wear tested to determine any necessary revisions. The feedback provided from these wear tests resulted in numerous modifications to die prototype last. The modified last and resulting articles of footwear were then in turn wear tested and additional changes were tiien made to die prototype last. This process was repeated until results were optimized with respect to die target population. The result of tiiis repeated and painstaking process is d e preferred embodiment of last 10 of the present invention and die articles of footwear 24 made therefrom.

It can be readily understood tiiat a variety of alternate or equivalent software, hardware, methods, processes and manufacturers could be used to derive die last of die present invention. Although not specifically shown, last 10 may also include a hinge as in die prior art lasts in order to simplify removal of the

article of footwear. It will also be obvious to tiiose of ordinary skill in die art tiiat numerous modifications may be made witiiout departing from the true spirit and scope of die present invention, which is to be limited only by die appended claims.

Claims

1. A last for making an article of footwear, said last comprising: a forefoot portion; a cone portion rearward of said forefoot portion; and a heel portion rearward of said cone portion; wherein said last has dimensions defined by a plurality of cross- sectional contours extending from proximate a proximal end of said heel portion to proximate a distal end of said forefoot portion; wherein said last dimensions are in accordance witii or proportional to said plurality of cross-sectional contours shown in Figs. 13-106.

2. The last of claim 1 wherein said cross-sectional contours are taken along consecutive parallel planes to a reference X-Y plane defined as Z being equal to 0.0.

3. The last of claim 2 wherein said cross-sectional contours are derived from ninety-four cross sections taken through said last, a first said cross section being located proximate said proximal end of said heel portion and a ninety-fourth said cross section being located proximate said distal end of said forefoot portion, each said cross-sectional contour corresponding to each said respective cross section through said last.

4. The last of claim 3 wherein said first said cross section is spaced 3mm or less from said proximal end of said heel portion, said ninety-fourth cross section is spaced 3mm or less from said distal end of said forefoot portion, and each said cross-sectional contour is spaced 3mm from an adjacent said cross- sectional contour.

5. The last of claim 1 wherein said cross-sectional contours of said forefoot portion define an enlarged toe box to comfortably accommodate a first toe.

6. The last of claim 1 wherein said cross-sectional contours of said

forefoot portion, said cone portion and said heel portion define a bottom edge

having a rounded periphery in order to accommodate a natural shape of a bottom surface of a human foot.

7. The last of claim 1 wherein said cross-sectional contours of said heel portion include a cone island defined by an upper surface of said heel portion, said cone island having a generally circular shape to accommodate a natural shape of a human ankle.

8. The last of claim 1 wherein said cross-sectional contours define a men's size 9 last, wherein said size 9 is graded in accordance witii or proportional to die stick lengtii, toe spring height, ball, and waist measurements represented in Fig. 10.

9. An article of footwear having a shape complimentary to the last of claim 1.

10. An article of footwear comprising: a shoe upper formed around a shoe last; and a shoe sole; wherein said shoe upper includes a heel area, an instep area and a forefoot area; and wherein said last has dimensions defined by a plurality of cross- sectional contours extending from proximate a proximal end of a heel portion of said last to proximate a distal end of a forefoot portion of said last; wherein said last dimensions are in accordance witii or proportional to said plurality of cross-sectional contours shown in Figs. 13-106.

11. The article of footwear of claim 10 wherein said cross-sectional contours are taken along consecutive parallel planes to a reference X-Y plane defined as Z being equal to 0.0.

12. The article of footwear of claim 11 wherein said cross-sectional contours are derived from ninety-four cross sections taken tiirough said last, a first said cross section being located proximate said proximal end of said heel portion and a ninety-fourth said cross section being located proximate said distal end of said forefoot portion, each said cross-sectional contour corresponding to each said respective cross section tiirough said last.

13. The article of footwear of claim 12 wherein first cross section is spaced 3mm or less from said proximal end of said heel portion, said ninety-fourth cross section is spaced 3mm or less from said distal end of said forefoot portion, and each said cross-sectional contour is spaced 3mm from an adjacent said cross- sectional contour.