US1454160A - Method of re-forming lasts - Google Patents

Description

May 8,1923.

J. FITZPATRICK :1- AL 'ua'raov or ICE-FORMING LA s'rs' 2 Sheets-Sheet 1 Filed Aug. 11. 1921 Fig.2-

M? j M Oman fir TDENEVS:

"May s, 1923.

- J. FITZPATRICK ET AL METHOD OF RE-FORMING LASTS I Filed Aug. v 11. 1921 2 Sheets-Sheet 2 i To all whom it concern:

Patented May 8, 1923. 1

UNITED STATES 11,454,160 PATENT OFFICE.

JEREMIAH FITZPATRICK, or BROCKTON, AND CHARLES H. rrrzPA'r-mcx, or non'rn ABrNo'roN, MASSACHUSETTS.

METHOD OF REFORMING LASTS.

Application filed August 11, 1921. Serial No. 491,615.

Be it known that we, JEREMIAH FITZPAT- nIoK,of Brockt-on,in the county of Plymouth and State of Massachusetts, and CHARLEs'H. F ITZPATRICK, of North Abington, in said county and State,both citizens of the United States, have invented a new and useful Improvement in Methods of Re- Forming Lasts, of which the following is a full, clear, and exact description, reference being had to the accompanying drawmgs, forming a part of this specification, in explaining its nature.

The present invention relates to a method of reforming lasts for boots or shoes. I

The object of the invention is to reform old lasts, or lasts that have been used, by recutting them usually only in part for correcting some slight fault in shape or form that makes the lasts valueless and has hitherto necessitated their being scrapped. In other words, in a general way the object is to conserve the wood or material from WhlCl'l the lasts are made.

It is hardly necessary to explain that innumerable lasts are thrown away which are perfectly good lasts excepting for some slight fault in shape. This difliculty is most commonly occasioned by change in style.

For example, the last may have" too pointed a toe or other characteristic no longer in vogue. One last thus faulty may be 'easlly remade and the fault corrected by'hand. Any such manual reformation of the last, however, is entirely impracticable inasmuch as it may be necessary to remake hundreds or even thousands of lasts in precise accordance with the manually reformed last. Our method accordingly is to the end that great numbers of lasts may be reformed quickly and economically to correspond precisel with the hand remade last or model.

That old lasts may be quickly and economically reformed to correspond with a hand remade last or model necessitates a very nice and accurate recutting of the last. When a last is initially formed from a block of wood according to a model no particular difliculty is experienced owing to the excess of wood from which the cut is first made. The problem is an entirely different one where there is no such excess of wood, and it becomes necessary that the knives or cutters should contact with the work only in part. This is referred to especially in relation to any of the well known types of lathe's for cutting lasts, for as will later .be explained, the whole method is carried out to the end that thelasts may be reformed or .recut on an ordinary type of last-turning lathe. 'The methodcomprises various steps that may be carried out by means of instruments forming no essential part of the ini vention but to tentative forms of which reference will later be made. We have accordingly shown in the drawings various instruments or devices for the purpose of making more clear various steps later to be referred to.

Fig. 1 is a plan of model centeringtable and last thereon.

Fig. 2 is the same as Fig. 1 with last partly in section to show borings. F g. 3 is a section on line 33 of Fig. 2.

' Flg. 4 is a side elevation of model centermg table with last thereon partlv in section to show borings. v I

F gs. 5 and 6 are front views of chucks. F gs. 7 and 8 are sideviews of chucks. i Fig. 9 is a diagrammatic plan of various details later to be referred to.

Assuming that a number of lasts of the same size and form are tobe changed, one of the lasts isfirst changed by hand into a model last, the same being gradually worked into the desired shape or form.

There is then established an axial centre for the model last and the same precise axial centre for all the other lasts, further rovision being made whereby the model ast and each of the other lasts may be placed in the last-turning lathe to rotate respectively on the precise axes thus obtained.

The precise axis for the model last and all the other lasts may be obtained as follows: A table 1 is provided on which any one of the lasts may rest. This table is provided with a number of upright pins 2 adjustable laterally thereon and each securable in adjusted position. For securing lateral adjustability and fixing of the pins the table has laterally riinning slots 3 therein along which the pins are movable, and the pins are'secured in adjusted position by providing each pin with a flange 4 contained in a groove 5 and with a nut and washer 6 on the threaded shank of the pin beneath the table which tightens against it as the nut is turned up.

The model last is first placed upon the table and held in place fixedly thereon by any suitable releasable overhead clamp (not shown) which is movable down to engage the top surface of the last. The clamp is made to enga the last under considerable pressure to sa eguard against accidental displacement. The pins 2 are now moved in to engage the last at different points along the outer edge thereof, preferably two pins engaging the last on opposite sides at the heel, ikewlse at the toe, while other pins may engage the last at opposite points adjacent the instep. The pins are brought into precise engagement with the last and there fixed;

.The pins thus located provide a form for all of the lasts so that any one last placed within the form thus provided has the precise. location on the table as did the model last.

Assuming that the model last is still located upon the table held by the clamp, means are now provided for establishing an axis for this last on which the last may rotate in a last-turning lathe. It is preferable that the definition of the axis may take the form of borings'8 in the model at the toe and heel, respectively, in order that the chuck or tool holding the last in the lathe may fit within the borings thus provided and in order that similar. borings may define the same precise axis for all the other lasts placed in the form as aforesaid. For

a purpose later to be referred to, separate spaced borings are formed in the heel and one at the toe, the axis running from the centre of the borin at the toe to a point precisely midway o the borings at the heel.

The axis thus formed in the model last may be an assumed axis. In other words, it is not necessary to ascertain the exact axis on which the last was originally'turned, but

placed in the form, clamped in place, bored and the axis of each thus defined.

The lasts thus prepared are now read to be placed in the last turning lathe. is lathe may be one of any well known type of which the lathe shown in Letters Patent of the United States No. 544,891 of August 20, 1895 is an'example, and in which cutters are controlled to turn a block of wood or other material into a last from off a'model wheel which follows the lines of a model last rotated in the machine. In the resent 1nstance the model last is placed in the machine in the place normally occupied by' the model, and the last to be reformed in the place normally occupied by the block when the last is primarily formed. According to the present operation however both lasts, meaning both the model last and the last to be reformed, must be placed in the machine in such manner that they will be maintained against displacement in all directions, including lateral displacement, endwise displacement, or displacement in a circular direction. To obtain such maintenance of the lasts chucks are preferably employed of the character shown in Figs. 7 and 8. There it will be seen that the chucks comprise. heads 10 from which project fingers or prongs 11, the chuck which supports the heel of the last having two fingers 11 which fit into the borings 8 already prepared in the heels, and the chuck supporting the toe of the last having a single finger fitting into the boring prepared in the toe. The chucks are fixed in the machine in the usual manner. When fixed in the machine the lasts are inserted between the chucks and the chucks then tightened on to the last until the ends of the lasts both at the heel and toe bearagainst the respective heads of the chucks. Thus retained the lasts will be maintained against displacement in all directions during the operation of the machine.

Both the model last and the last worked upon or reformed should be located in the machine to occupy like positions. the one with relation to the model wheel 12 and thevother or last to be reformed with relation to the cutter 13.v (See Fig. 9.)

Before the cutting operation actually takes place it is necessary that the cutter be positioned to en age the last to be worked upon at precisely t e same point on the last as the model wheel is engaging the model last. (See Fig. 9.) Such exact positioning of the cutters or models is obtained through the manipulation of the machine and such auxiliary measurements as may be necessary. Usually in such connecltion the: measurement is taken with relation to the exact centers of both cutter and the model wheel in relation to the respective lasts. All

having been thus prearranged the cutting is effected in the usual manner, the. last worked u on being reformed according to fixed by borings therein for giving it the same determined axis as the number 7 last. For obtaining such axis in the number 8 last it will be necessary to laterally displace the pins on the centering table to accommodate the increased size of the last and also elevate 1 the borings in proportion to the increased size of the last as may be obtained by measurement. The elevation of the borings may be done either by lowering the table in relation to the boring'tools or by elevating the tools. The axis having thus been determined the method is carried out as previously described, the essential idea being that both the number 7 and number 8 lasts may be arranged to turn in the lathe on the same relative axis, the method being otherwise carried out as previously described.

Having thus fully described our invention, we claim and desire to secure by Letters Patent of the United States:

1. The method of reforming a lot of lasts in a last turning lathe having a model fol? lower and a cutter, comprising the making of a model last from one of said lot, fixing said model last whereby it may be arranged to turn in said lathe on a determined axis, fixing the other lasts of the lot whereby each may be arranged to turn in said lathe on a determined axis the same as that to the model last, fixing the model last and successively each of the other lasts in the lathe to turn on their respective determined axes Without displaceability in any direction, and whereby also the model last and last to be reformed will occupy like relative positions the one to the model follower and the other to the cutter, otherwise arranging whereby the model follower and cutter will engage respectively the model last and last to be reformed at like points on the respective lasts during the cuttings, and then cutting in the usual manner.

2. The method of reforming a lot of lasts in a last turning lathe having a model follower and cutter according to a model last, comprising the fixing of said model last whereby it may be arranged to turn in said lathe on a determined axis, fixing the other lasts of the lot whereby each may be arranged to turn in said lathe on a determined axis the same as that to the model last, fixing the model last and successlvely each of the other lasts in the lathe to turn on their respective determined axes without displaceability in any direction, and whereby also the model last and last to be reformed will occupy like relative positions the one to the model follower and the other to the cutter, otherwise arranging whereby the model fol lower and cutter will engage respectively the model last and last to be reformed at like points on the respective lasts during the cuttings and then cutting in the usual manner.

3. The method ofreforming a lot of lasts in a last turning lathe having a model follower and cutter according to a model last, comprising the fixing of said model last by borings therein whereby it may be arranged to turn in said lathe on a determined axis, fixing the other lasts of the lot byborings therein whereby each may be arranged to turn in said lathe on a determined axis the same as that to the'model last, fixing the model last and successively each of the other lasts in the lathe at the points of the borings therein to turn .on their respective determined axes without displaceability in any direction, and whereby also the model last andlast to be reformed will occupy like relative positions the one to the model follower and the other to the cutter, otherwise arranging whereby the model follower and cutter Wlll engage respectively the model last and last to be reformed at like points on the respective lasts during the cutting and,

then cutting in the usual manner.

JEREMIAH FITZPATRICK. CHARLES H. FITZPATRICK.

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