US3673623A

US3673623A - Improved last for shoe production

Info

Publication number: US3673623A
Application number: US50083A
Authority: US
Inventors: Itzchak Zohar
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-07-10
Filing date: 1970-06-26
Publication date: 1972-07-04
Anticipated expiration: 1989-07-04
Also published as: IL32598A; IL32598A0; DE2033719A1; DE2033719B2

Abstract

A last for shoe production. In that last there is defined a metartasal line being the line corresponding to that line of the foot sole connecting the joints which separate the metartasus from the phalanges. The last is characterized by at least one bulge at the metatarsal line region so designed that when the last is rested on a horizontal surface the toe portion remains clear of that surface while when the last is tilted by lifting the heel portion by the height of the designated heel, the toe portion touches the surface. It is further characterized by the fact that a cord extending between the two end points of the metartasal line is normal to the median vertical plane of the last.

Description

United States Patent Zohar July 4, 1972 54 LAST FOR SHOE PRODUCTION [72] Inventor: Itzehak Zohar, 7l Sokoloff Street, Holon,

Israel [22] Filed: June26, 1970 [21] Appl.No.: 50,083

[30] Foreign Application Priority Data Levitt ..l2/l33 R Freeman ..l2/l33 R [57] ABSTRACT A last for shoe production. In that last there is defined a metartasal line being the line corresponding to that line of the foot sole connecting the joints which separate the metartasus from the phalanges. The last is characterized by at least one bulge at the metatarsal line region so designed that when the last is rested on a horizontal surface the toe portion remains clear of that surface while when the last is tilted by lifting the heel portion by the height of the designated heel, the toe portion touches the surface. It is further characterized by the fact that a cord extending between the two end points of the metartasal line is normal to the median vertical plane of the last.

1 Claim, 5 Drawing Figures PATENTEnJum 1912 3,673,623

SHEET 10F 2 INVENTOR ITZCH AK ZOHAR BY w wm ATTORNEYS PATENTEDJUL 41912 3, 678 623 SHEET 20F 2 Fl G. 4

F44 INVENTOR ITZCHAK ZOHAR Fl 6 BY M v ATTORNEYS LAST FOR SHOE PRODUCTION The present invention concerns shoe production and lasts for use therein. The lasts according to the invention can be used both for manual and mechanical shoe production, and may serve for the production of ordinary and orthopedic shoes.

In the following specification and claims the imaginary line on the sole of the last which corresponds to the line on the foot sole connecting the joints separating the metatarsus from the phalanges will be referred to as metatarsal line." The metatarsal line is a curved line which bulges in the direction of the toes. The points at which the metartasal line intersect the edges of the last will be referred to in the following specification and claims as the metatarsal edge points.

Considering the shape of the human foot, it is clear that in its normal position with the heel portion resting on a horizontal reference surface, the metatarsal line on the sole of the foot is in contact with such surface. Because a last corresponds to a human foot, the heel portion of the last and the metatarsal line on the last engage a horizontal reference surface when the last rests thereon, permitting an imaginary plane normal to such surface to be passed through the metatarsal edge points of the last. In this plane, the metatarsal edge points can be connected, on the one hand, by an arcuate line extending on the surface of the last constituting the sole, and on the other hand, by an imaginary straight line which fonns the chord of said arcuate line. The chord will be referred to in the following specification and claims as The Chord of the Metatarsal Edge Points; and the arcuate line as The Arcuate Metatarsal Line." At least a portion of the last mentioned line engages the reference surface when the last rests therein. The plane containing the chord of the metatarsal edge points and the arcuate metatarsalline will be referred to as The Metatarsal Plane."

In the following specification and claims reference is also made to a median vertical plane, which is defined as being the plane normal to the reference surface, which plane, when the last rests on such surface, passes through an imaginary straight line connecting the apex of the upper heel portion contour of a last with a point of the last which in a corresponding shoe overlaps the position of the edge of the second toe. The median vertical plane and the metatarsal plane interect along a line which is perpendicular to the horizontal reference surface when the last rests thereon. The line defined by these intersecting planes is referred to as The Median Vertical Line.

The new last according to the invention is characterized by:

a. One or more bulges at the metatarsal line region so designed that when the last is rested on a horizontal surface the toe portion remains clear of that surface while when the last is tilted by lifting the heel portion by the height of the designated heel, the toe touches said surface; and

b. the cord of the metatarsal edge points is normal to the median vertical line and is bisected thereby.

By both its characteristics the last according to the invention is distinguished from conventional lasts in which even when the heel portion is lifted by a height corresponding to the designated heel, the toe portion does not touch the surface on which the last rests at the same time the arcuate metatarsal line is spaced from such surface, and the cord of the metatarsal edge points is not normal to the median vertical line and is not bisected thereby.

The lasts according to the invention are applicable for manual and mechanical shoe production. In the case of manual shoe production the sole of the last preferably corresponds substantially to the sole of the foot and may, if desired, be made to measure, in particular in the case of the production. of orthopedic shoes. In the course of manual manufacture with the aid of a last according to the invention, the insole will first be made and temporarily be attached to the last and the shoe is then produced in the conventional way.

Where the last according to the invention is to be used for mechanical shoe production, its sole will preferably not oor respond to the sole of the human foot, but rather substantially to the lower face of the insole so that the shoeremaining when thelast is withdrawn has still to be filed with an insole.

Experience has shown that shoes produced with the aid of lastsaccording to the invention are superior to conventional shoes as regards their adaptation to the natural pose and shape of the feet. They consequently impart to the wearer greater stability and comfort and are of much longer duration than conventional shoes.

The invention thus also consists in a method of shoe production wherein a last as specified is employed.

Theinvention further provides shoes produced with the aid of lasts as specified.

The invention is illustrated, by way of example only, in the accompanying drawings in which: I

FIG. 1 is an elevation of a conventional last shown in two diflerent positions;

FIG. 2 isan elevation of a last according to the invention shown in two different positions;

FIG. 3 is aplan view of alast according to the invention resting on a horizontal reference surface and showing the metatarsal line and the cord ofthe metatarsal edge points;

FIG. 4 is a vertical central section of a last according to the invention along line IV-IV of FIG. 3, also showing in perspective the outlines of the sole; and

FIG. 5 is a section'along line V-V in FIGS. 3 and 4.

As shown in FIG. 1, the conventional last 1 comprises a bulging portion 2 in the metatarsal line region, a heel portion 3, and a toe portion 4. When this last is rested on a horizontal surface, the toe portion 4 remains clear of the surface. If now the heel portion 3 is lified by a height corresponding to that of the designated heel into theposition shown in dashed lines, the toe portion 4 still remains clear of the surface. Referring now to FIG. 2 which shows a last according .to the invention, it is seen that this last 5 comprises also a bulging portion 6 at the metatarsal line region, a heel portion 7 and a toe portion 8. When the last is rested on a horizontal surface, bulging portion 6 is engaged with such surface, but the toe portion 8 remains clear of .that surface. If now the heel portion 7 is lifted by a height corresponding to that of the designated heelinto the position shown by way of dashed lines, bulging portion 6 clears the surface and the toe portion 8 touches thefloor, as distinct from the case in FIG. 1. Because the bulging portion 6 of the last establishes the location of the arcuate metatarsal line on the sole of the last, the above described elevation of portion 7 also elevates the metatarsal line from the surface.

Turning now to FIG. 3, it is seen that the metatarsal line 9 intersects the edges of the last at two points 10 and 11 which are the metatarsal edge points as herein defined. The metatarsal edge points can be connected by a straight line 12 which is the cord of the metatarsal edge points, again as herein defined.

In FIG. 3 the line IV-IV connects the apex 15 of the upper heel portion contour with a point 16 which in a corresponding shoe made with the aid of this last overlaps the position of the edge of the second toe. A vertical section through this line yields the median vertical plane as herein defined, which plane is shown in FIG. 4 and indexed 14, and which is also shown by way of a dash-dotted line in FIG. 5.

Referring to FIGS. 4 and 5 it is seen that the metatarsal edge points 10 and 11 are connected by an arcuate line 13 running along the sole surface and defining together with the line 12 the vertical metatarsal plane previously defined, with line 12 being the cord of arc 13.

Median vertical plane 14 of'the last, and the vertical metatarsal plane intersect each other as shown in FIG. 5. As is evident from this figure, chord I2 is perpendicular to the line defined by the intersection of the last mentioned planes, and is bisected by the median vertical plane. In fact, thesection of the last at the metatarsal plane is symmetrical about the line defined by the intersection of this plane with the median vertical plane.

As best seen in FIG. 4, elevation of heel portion 7 above a horizontal reference surface by an amount corresponding to that of the designated heel causes the arcuate metatarsal line median vertical line defined by the intersection of the 13 to be raised clear of the reference surface. median vertical plane of the last with the metatarsal I claim: plane, and is bisected thereby; L A last C p g: d. said body being further constructed and arranged so that a 3 heel P at one thereof, a toe P 5 when the sole thereof rests on a horizontal reference surtion at the other end thereof, a bulging portion at the face, said we portion remains f said surface metatarsal line region adjacent said toe portion, and a the arcuate metatarsal line cngases'said surface, and

sole; b. the bulging portion of the said body containing the metatarsal edge points and the arcuate metatarsal line which together define the metatarsal plane; c. said body being constructed and arranged so that the cord of the metatarsal edge points is perpendicular to the when said heel portion is lifted by a height corresponding to that of the designated heel, the toe portion engages said surface and the arcuate metatarsal line is clear of said 1 surface.

Claims

1. A last comprising: a. a body having a heel portion at one end thereof, a toe portion at the other end thereof, a bulging portion at the metatarsal line region adjacent said toe portion, and a sole; b. the bulging portion of the said body containing the metatarsal edge points and the arcuate metatarsal line which together define the metatarsal plane; c. said body being constructed and arranged so that the cord of the metatarsal edge points is perpendicular to the median vertical line defined by the intersection of the median vertical plane of the last with the metatarsal plane, and is bisected thereby; d. said body being further constructed and arranged so that when the sole thereof rests on a horizontal reference surface, said toe portion remains clear of said surface, and the arcuate metatarsal line engages said surface, and when said heel portion is lifted by a height corresponding to that of the designated heel, the toe portion engages said surface and the arcuate metatarsal line is clear of said surface.