US3083386A - Shoemakers' lasts - Google Patents

Description

A ril 2, 1963 1.. D. RAYMOND SHOEMAKERS LASTS Original Filed June 10. 1960 INVENTOR LORENZO n. RAYMOND Y Olud M ATTORNEYS United States Patent 0 M 3,933,336 SHDEMAKERS LA TS Lorenzo Bat/id Raymond, North Baiwyn, Victoria, Austraiin, assignor to G. N. Raymond Limited, oliing= wood, Victoria, Austraiia, a company of Victoria Original application June 19, 15360, Ser. No. 35,173, new Patent No. 3,034,169, dated May 15, 1962. Divided and this application Mar. 21, 1962, Ser. No. 181,332

Cia'nns priority, appiication Anstraiia Feb. 5, rate iaims. (Cl. l2-145} This invention relates to shoemakers lasts.

In the normal process of manufacturing shoes with leather soles, as distinguished from those having vulcanized soles, the last is generally constructed of wood and is so designed that the heel portion may be pivoted on the fore part portion thus causing a shrinking or decrease in the overall length so that the last may be removed from the shoe which has been formed around it.

Such prior types of last have usually been made of a single piece of hard and fine grained wood and have generally been divided, for example by a band-saw or similar tool, into two portions which are pivoted to allow such relative movement as is necessary to permit withdrawal of the last from the completed shoe.

Prior types of last have generally achieved such pivoting motion by employing one or more metal links retained at or adjacent their extremities by a plurality of pins, the links and associated pins being so disposed that the relative rotation of the heel and fore part portions will result in a general longitudinal contraction of the last as a whole.

Blocks from which lasts are made contain a substantial excess of wood so that a variety of heights of heels and widths of fittings may be formed from each block. Usually one particular length of block will provide only for a limited number of sizes, there being four or five blocks required to cover the full range of childrens, womens, and mens lasts.

The comparatively large volume of the blocks hitherto generally found necessary presents difliculties in drying the wood to a moisture content of the required uniformity or homogeneity.

Thus in the past difliculty has often been experienced in obtaining lasts, particularly when out from the inner portion of the block, which will not deform by changnng shape in excess of prescribed limits, due to absorption of atmospheric moisture.

Furthermore, it has hitherto been generally found that unless the position of the pins associated with the links mutually retaining the heel and fore part portions is closely controlled, difiiculty is experienced in effecting the pivoting movement necessary prior to removal of the last, and an attempt to do so may cause a breakage in the wood, especially in the region of the pins and links, thus resulting in a high percentage of reject lasts and hence a substantial wastage of material. Should the pins however be too far apart, the assembly comprising the fore part and heel portions will be excessively loose causing inadequate support of the shoe during processing operations.

The primary object of this invention is to provide a last which is readily adaptable to mass production, and which will permit a similar cross section of timber to be used for the heel and fore part sections and which will enable reduced stocks of last blocks to be held as a standard timber section to be used for both the heel and fore part sections.

Another :object is to provide a last which will allow a greater degree of mechanical precision of the portions in Efibdfidh Patented Apr. 2, i963 the rou h state b machines bein more readil capable ofg y a gripping the regularly shaped Wood sections.

Another object is to provide a method of producing a last, which method materially reduces the amount of labour and time hitherto generally required in the production of known types of last.

Further objects of the present invention are to reduce the problem of drying and also the cost and time of manufacture by having less timber to remove in the roughing and finishing operations.

The above and other objects and advantages of the invention will become apparent hereinafter.

Accordingly the present invention provides an improved last comprising a woden fore part, a wooden heel part and two intermediate portions, moulded from plastic material, which are secured at their remote ends to said fore part and said heel part respectively, and are interconnected at their facing ends to enable the last to be broken preparatory to removal of a lasted shoe therefrom.

it is preferred that the wooden fore part and the wooden heel part have tongues or like portions projecting rearwardly and forwardly, respectively, the intermediate portions being moulded so as to fill the gaps between the tongues and thus bond the intermediate portions to their respective wooden parts. This embodiment thus provides a large interface between the heel and fore parts and their associated intermediate portions, and hence a large bonding surface, whose area depends upon the number and depth of the tongues.

The present invention further provides a method of producing a last, comprising moulding the two intermediate portions from plastic material, adhesively mounting each said portion on a wooden block, linking the plastic portions so as to allow limited relative movement therebetween, and shaping the blocks and their associated plastic portions into a last with one block forming a heel part and the other, a fore part, the extent of said relative movement being sufi'icient to allow for breaking the last.

By breaking the last, is meant causing such relative movement of its component parts from. their operative or unbroken position, as is necessary to withdraw a lasted shoe from the last. Such movement may be substantially translational, using, for example, a planar interface between the intermediate portions, or may involve a relat-ive rotation between the components, the latter being achieved when a curved interface is employed. In any event it is highly desirable to provide a toggle action between the operative and inoperative positions, that is, an action such that although the last is stable in either position, a substantial amount of force is required to break or unbreak it.

The pivot portions may be moulded to close tolerances thereby permitting a greater control over the tension mutually retaining the heel and fore part sections.

But in order that the invention may be better understood reference will now be made to the accompanying drawing which is to be considered as part of this specification and read herewith.

FIGURE 1 shows a preferred form of last in accordance with this invention, in its operative position.

FIGURES 2 to 6 inclusive illustrate various representative steps in a preferred embodiment of the process provided by the present invention.

The last illustrated in FIGURE 1 includes a wooden fore part 7 having rearwardly extending tongues 8 with intervening gaps 9, and a wooden heel part it) with forwardly extending tongues 11 spaced by intervening gaps 12. Two intermediate portions 13, 14 associated respectively with parts '7 and it are plastic mouldings,

acsasse 3 the plastic material filling the gaps between the tongues so as to bond the intermediate portions 13, Il ito their respective wooden parts '7, it).

Each intermediate plastic portion has a cavity suitably located to accommodate link means for interconnecting them. The cavity, in the drawing visible in the forward portion only, advantageously comprises a tran verse bore communicating with a longitudinal recess 16, the recesses having apertures oppositely disposed in the facing ends 1'7, 1? of the intermediate portions, and the articulative means comprising a link it) perforated adjacent its ends by perforations 19a, 1% the link being adapted to bridge the intermediate portions. Each transverse bore 15 is fitted with a pin, the pins passing through perforations 19a, 1% so that the interconnection affords a toggle action between the operative and broken positions of the last.

I The last is advantageously provided with a metal, fibre or leather strip 28 located on an upper surface of the heel part it; and corresponding intermediate portion 14, this strip forming a strengthening base for a thimble-receiving shaft 29. When it is desired to break or unbrean the last a thimble may thus be readily inserted to retain the heel part in a substantially fixed position, while the fore part is moved relatively to it.

Referring now in particular to FlGURES 2 and 3, a preferred method of forming a last comprises shaping end parts 29, 21 of two wooden blocks into a plurality of tongues 22, 23 respectivelyQthe projections being spaced by intervening gaps 2 25 respectively. Moulds (not shown) having appropriate moulding faces are mounted so as to overlie the shaped end parts, and plastic material is compressively injected into each mould so that the material fills the gaps 2d, 25 to provide a gripping relationship between the moulding and the associated block. Such moulding will in almost every case involve a deformation of the tongues in the respective wooden block, and the irregularities introduced materially assist the bonding adhesion between the molding and the corresponding block.

Each mould has provision for leaving in the resultant moulding a cavity comprising a transverse bore communicating with a longitudinal recess (indicated by the dotted lines, FIGS. 4 and 5), to accommodate link means for interconnection of the plastic portions. The moulded face of the mould is such that the resultant plastic mouldings will each be provided with a bearing surface, eg. 26, shaped complementarily to a bearing surface 27 on the other moulding so that during the relative movement of the portions connected by the link means, the complementary bearing surfaces 25, 27 remain substantially incontact.

When the plastic material has set to the required degree the moulds are removed and the link means engaged whereby the plastic portions together with their associated blocks are connected as shown in FZGURE 6.

It may be desirable to mould one of the plastic portions with its pin already in position passing through the link. In this case the plastic portions may be connected simply by placing these portions adjacent one another with their complementary surfaces 26, 27 in engagement and the link positioned in both recesses. To complete the connection it now only remains to insert the pin in the other intermediate portion so as to pass through the vacant perforation in the link 19. The structure shown in FIGURE 6 is then shaped into the desired form of last with one block, for example 21, forming the fore part 7 and the other 2d, the heel part it It will be apparent from the above that the present invention will allow similar cross sections of timber to be used for the heel and fore part sections thus eifecting a substantial saving in time.

The invention will also enable reduced stocks of last blocks to be used as the standard section of timber em- A ployed for both heel and fore part sections and will permit of an improved degree of mechanical precision of the portions in the rough state by machines being more readily capable of gripping the timber sections. Furthermore, the number of machine operations hitherto required in forming the pivot portion, and also the problems associated with drying, are materially reduced.

If desired each intermediate portion and its corresponding wooden part may be formed independently. To this end, the plastic portions are formed in moulds which are advantageously shaped so as to provide in the resulting moulding, in addition to the bearing surface and the cavity accommodating the link means, a plurality of tongues and intervening gaps. Thus, the moulds may have a configuration such as shown by the member overlying end part 24} in FIGURE 4. The blocks destined to form the fore and heel parts in the last are shaped so as to provide on each a surface adapted to register with a complementary surface of the correspond ing intermediate portiom'for example, if the moulding has the tongue and groove configuration shown in FIG- URE 4, then the complementary portion of the corresponding block it? is shaped such as shown in FIGURES 2 and 4. Each intermediate portion is then mounted on the relevant end part with their respective complementary surfaces in abutting relationship. Such mounting is preferably effected by application of an adhesive to the surfaces. The intermediate portions may then be connected, for example by the link means described above, and the structure comprising the connected portions and blocks shaped into the desired form of last, one block forming a forepart and the other, a heel part, the extent of relative movement between each intermediate portion and block being sufficient to allow for breaking the last, as previously described.

In addition, those portions of the last whose shape must be precisely controlled may be readily mass produced and the over-all cost of manufacture is substantially reduced, since there is now less timber to be removed, in the roughing and finishing operations.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A method of producing a last, comprising the steps of providing two wooden blocks, moulding and securing an intermediate portion of plastic material on each wooden block, linking the plastic portions so as to allow limited relative movement therebetween, and shaping the blocks and their associated plastic portions into a last with one block forming a heel part and the other, a fore part, the extent of said "elative movement being sufiicient to allow for breaking the last.

2. A method of producing a last according to claim 1 wherein said plastic intermediate portions are moulded directly on said wooden blocks.

3. A method of producing a last according to claim 1 wherein said plastic intermediate portions are first moulded apart fromthe wooden blocks and subsequently secured to the wooden blockswith an adhesive material.

4. A method of producing a last, comprising shaping two blocks of wood to provide on each a surface adapted to register with a surface of an associated intermediate last portion, moulding from plastic material an intermediate portion for association with each block, each intermediate portion having a cavity suitably located to accommodate link means whereby the intermediate portions are adapted to be connected in movable relationship, said portions each having a bearing surface shaped complementarily to a bearing surface on the other intermediate portion so that during relative movement of the portions the complementary bearing surfaces remain substantially in contact, removing the moulds, attaching each intermediate portion to the corresponding block, connecting the intermediate portions, and shaping the structure comprising the blocks and solidified intermediate portions into the desired form of last, one block forming a fore part of said last, and the other, the heel, the extent of relative movement between each intermediate portion with its associated block and the other portion and block being sufficient to allow for breaking the last.

5. A method of producing a last, comprising shaping an end part of each of two blocks of wood into a plurality of tongues with intervening gaps, moulding on each shaped end part an intermediate portion of plastic material by mounting a mould so as to overlie the end part of the corresponding block, injecting and compressing the plastic material into the mould so as to till the gaps and provide a gripping relationship between the completed moulding and associated wooden block, each mould having provision for leaving in the resulting moulding a cavity suitably located to accommodate link means whereby the intermediate portions are adapted to be connected in movable relationship, said moulded portions each having a bearing surface shaped complementarily to a bearing surface on the other moulded portion so that during relative movement of the portions the com plementary bearing surfaces remain substantially in contact, removing the moulds, connecting the intermediate portions and shaping the structure comprising the blocks and solidified intermediate portions into the desired form of last, one block forming a fore part of said last, and the other, the heel, the extent of relative movement between each intermediate portion with its associated block and the other portion and block being sufficient to allow for breaking the last.

6. A method of producing a last, comprising shaping an end part of two blocks of wood into a plurality of tongues with intervening gaps, moulding from plastic material an intermediate portion for association with each block, each intermediate portion having a plurality of tongues with intervening gaps adapted to fit into, and receive, respectively, the gaps and tongues in the corresponding block, a cavity suitably located to accommodate link means whereby the intermediate portions are adapted to be connected in rotatable relationship, and a bearing surface shaped complementarily to a bearing surface on the other intermediate portion so that during relative movement of the portions the complementary bearing surfaces remain substantially in contact, adhesively mounting each intermediate portion to the corresponding block, connecting said intermediate portions and shaping the structure comprising the connected portions and blocks into the desired form of last, one block forming a fore part of said last and the other, a heel part, the extent of relative movement between each intermediate portion and block being sufiicient to allow for breaking the last.

7. A method of producing a last, comprising shaping two blocks of wood to provide on each a surface adapted to register with a surface of an associated intermediate last portion, moulding from plastic material an intermediate portion for association with each block, each intermediate portion having a cavity comprising a transverse bore adapted toreceive a pin, the bore communieating with a longitudinal recess, the recesses of the respective intermediate portions when placed in registration being arranged to accommodate a link bridging the intermediate portions, the link being perforated adjacent each of its ends to receive the pins, one of the pins and the link being moulded in situ in one of the intermediate portions with said one pin being received in one of the perforations of the link, the intermediate portions each having a bearing surface shaped complementarily to a bearing surface on the other intermediate portion so that during relative movement of the portions the complementary bearing surfaces remain substantially in con tact, removing the moulds when the moulded intermediate portions have solidified, connecting the intermediate portions by bringing said portions together so that the link is received also in the cavity of the other intermediate portion, inserting the other pin in the transverse bore of the cavity in the last-mentioned portion, and shaping the structure comprising the blocks and solidified intermediate portions into the desired form of last, one block forming a fore part of said last, and the other, the heel, the extent of relative movement between each intermediate portion with its associated block and the other portion and block being sufiicient to allow for breaking the last.

8. A method of producing a last, comprising the steps of producing two wooden blocks having parts of their surfaces shaped complementarily to a junction surface of equal area on a plastic portion to be rigidly secured to the respective wooden block with the respective junction surfaces in contact over their whole areas, securing said wooden blocks and said plastic portions at their complementary junction surfaces, linking the respective plastic portions to each other so as to allow limited relative movement therebetween, and subsequently shaping the blocks and their associated plastic portions into a last with one block forming a heel part and the other, a forepart, the extent of said relative movement being suflicient to allow for breaking the last.

References Cited in the file of this patent UNITED STATES PATENTS 3,034,160 Raymond May 15, 1962

Claims (1)

1. A METHOD OF PRODUCING A LAST, COMPRISING THE STEPS OF PROVIDING TWO WOODEN BLOCKS, MOULDING AND SECURING AN INTERMEDIATE PORTION OF PLASTIC MATERIAL ON EACH WOODEN BLOCK, LINKING THE PLASTIC PORTIONS SO AS TO ALLOW LIMITED RELATIVE MOVEMENT THEREBETWEEN, AND SHAPING THE BLOCKS AND THEIR ASSOCIATED PLASTIC PORTIONS INTO A LAST WITH ONE BLOCK FORMING A HEEL PART AND THE OTHER, A FORE PART, THE EXTENT OF SAID RELATIVE MOVEMENT BEING SUFFICIENT TO ALLOW FOR BREAKING THE LAST.

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