US888261A - Hinged last. - Google Patents

Description

PATENTED MAY 19, 1908.

C. P. PYM.

HINGED LAST.

APPLICATION FILED AUG. 2.1907.

.Zwarai'tonakwrle-fij lgyim 2 been recognized as UNITED STATES PATENT OFFICE.

CHARLES F. PYM, OF ESSEX, ONTARIO, CANADA, ASSIGNOR TO KRENTLER-ARNOLD HINGE LAST COMPANY, OF DETROIT,

MICHIGAN, A CORPORATION OF MICHIGAN.

HINGED LAST.

No.-'sss,261.

Specification of Letters Patent.

Patented May 19, 1908.

To all whom it may concern.

I Be it known that I, CHARLES F. PYM, a subject of the King of Great Britain, and resident of Essex, in the county of Essex and Province of Ontario, Canada, have invented an Improvement in Hinged Lasts, of which the folowing description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My present invention aims to secure great rigidity and strength, and at the same time simplicity of construction and operation, in a boot and shoelast. The hinged last has long the most desirable form of last, but, in view of the fact that the hinging of the heel-part and forepart must necessaril be effected at tliewaist or middle of the fast, which is the very part of the last which should be left as strong as possible, and which should not be weakened by cutting away the wood or introducing a hinge, pivot pins, etc., the problem of making a practical commercial hinged last capable of enduring the rough usage and great strain brought upon a last in a shoe factory, has proved exceedingly difficult. The result has been that as a rule those lasts which have been simple in construction have been lacking in strength, and those lasts which have been sufficiently strong have been complex or unduly expensive. Accordingly, I have succeeded in devising a construction at once simple and ex-,

ceedingly strong, in which I employ a relatively broad vertical hinge-plate occupying a narrow kerf or slot in the forepart and a simi lar slot in the heel-part for a sufficient vertical distance to resist effectively all wrenching and twisting strains, and I provide overlapping approximately horizontal shoulders extending entirely across the abutting walls of the forepart and heel-part at the horizontal middle or largest horizontal diameterof the waist, thereby affording the greatest overlapping contact of the wood of the forepart and the wood of the heel-part when the last is bottom up as required in actual shoe shop use. This enables me to place the pivot of the hinge low down in the forepart so as to secure a quick-shortening swinging movement without introducing any substantial weakness into the last, because, in my construction, the hinge is not required to sustain rectly by the wood at the bulge or widest portion of the waist of the last as explained.

In the drawings, in which I have shown a preferred embodiment of my invention, Figures 1 and 2 are fragmentary views in side elevation of a last in its bottom up position as required in use in shoe factories, Fig. 2 being broken out at the side for clearly showing the internal construction; and Fig. 3 is a vertical cross section through the hinge pivot of the last.

My last is so simple in its construction that it may be explained in a few words: The forepart 1 and heel-part 2 are joined by a late hinge 3 secured rigidly in the heel-part y a transverse pin 4 and a heavy rivet or bolt 5, and free to turn in the forepart on a heavy tool-steel pin 6, narrow kerfs 7, 8 being pro vided respectively in the forepart and heel part to receive said hinge-plate. The hingeplate extends upwardly toward the top of the last at 9 throughout the wider portion of the last where the greatest strength is afforded for resisting twisting strains such as are due to the rolling and rocking leveling pressures which proceed lengthwise along the bottom of the shoe in the process of bottom-leveling. The heel-part is severed from the forepart alon an irregular line of cut forming a top gap ounded by a curvature 10 on the forepart and 11 on the heel-part, which fit into each other when the last is collapsed, as shown in Fig. 1, and a preferably straight lower portion 12. and approximately horizon tal out 13 connecting the upper portion with said straight lower portion. This severing arrangement provides overlapping shoulders 14, 15, shown separated in Fig. 1 and 1n mutually supporting contact in Fig. 2. This broad and approximate] horizontal ledge is located in a horizontal pfiine above the pivot pin 6 and between the two securing pins 4, 5, and is at the widest part or bulge of the waist, as best-shown in Fig. 3. Thus, when the last is subjected to pressure, it is evident, viewing Fig. 2, that the heavy shoulder 15 of the heelpart receives practically all the vertical strain, said strain being transmitted thereto by the correspondingly heavy shoulder 14, both of said shoulders extending entirely across the last at the widest part of the waist as stated. This relieves the pivot pin 6 of most of the strain which has hitherto been brought upon it, so that there is no longer the liability of its pulling the wood of the forepart out endwise. The direction of the cut 12 also aids somewhat, as it laps over the heel-part slightly.

My invention is subordinate to the Oscar Heath atent,'No 652,616, of June 26, 1960, over w 'ch it is an improvement. In that atent the forepart and heel-part are provided with opposite overla ping portions at the hinge eye or intle of a eaf hinge set fiatwise longitudinally in the last, said construction being provided for relieving the hinge of certain strains, but said constructlon merely increased the tendency of the last to split, lnasmuch as it brought the entire vertical pressure in one and the same horizontal plane coinciding with the transverse saw cuts occu ied by the hinge leaves. Thus, in the Heat construction the twisting strains and the vertical strains were both brought to bear along a single weakened horizontal lane. In my construction these strains are distributed throughout all the wood of the waist of the last, and do not center upon any one plane or point, the twisting str'aln being largelyborne by the vertical extension 9 of the hinge-plate and its engaging slot, and to some extent transmitted to the heavy steel pin-6 and its supporting-wood, said pin extending transversely through the body of the last adjacent the lower part of the forepart, and the vertical strain being taken by the 4 horizontally extending shoulders 14 and 15,

which are'not in line with any pivot or hinge as in Heath, but he in a horizontal plane which does not include any of the transverse pins 4, 5, 6, but, on the contrary, comes at the widest bulge portion of the waist entirely independent of any natural splitting plane,

such as is caused by the location of thehinge in the Heath construction. Also, the construction is such that the heel-part swings instantly entirely clear of the forepart for uick shortening with minimum resistance. he main features of the invention reside,

I however, in distributing the joint end strains throughout different localities in the wood, so that no disastrous strain can possibly come at one point, and especially so that the strains do not come alon any natural line of cleavage or splitting of tl ie wood, said distribution of strains being accomplished by loeating a wide or deep vertical hinge-plate centrally in the widestpart of the wood of the last-waist, providing the front lower corner of said vertically extending plate witha heavy transverse ivot in, and forming the overlapping shou ders ocated intermediate the horizontal planes of the various pivot and retaining pins, said shoulders each having a vertical backing of solid wood which projects forward beyond the vertical planeof the front edge of the respective projection, or in other words, preferably overhangs or underhangs as the case may be, t. e. the shoulder 15 has an overhanging solid body sesamof. wood above it in the heel-part, so that the heelart thereby possesses maximum strength 0 solid uncut wood, and the shoul- 'der 14 has an underhanging or rearwardly projecting solid body of wood below it in the orepart, so that the forepart thereby possesses maximum strength of solid uncutwood.

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

1. A hinged last, having its forepart and heel-part connected by a deep hingelate set vertically in the contiguous walls 0 said last parts, vertical engagement within the forepart sub-1 said hinge-plate having a wide stantially commensurate with the bulging I portion of the fore art having large trans:

verse width, and a eavy pivot in extend-n ing through the lower part of t e forepart' arlid the lower forward corner of said hingeate, lieel-part are transmitted by said hinge-plate in a vertical plane to the central portion of the enlarged part of the rear end of the fore art andby said heavy transverse pin in a orizontal plane to the lower-rear portion of the forepart, said hinge-plate being rigidly secured in the heel-part by two transverse pins located respectively in the rear upper corner and rear lower corner of the hingelate and extending transversely through the eel-p art,

whereby the twisting strains of the" said heel-part and forepart being severed by lines of cut forming approximately horizontally overlapping shoulders located in a horizontal plane above the lower heel-part pin and said pivot pin and below the upper heel-part pin, and a gap betweensaid heel-part and forepart extending upwardly from the front nor' mally contacting ends of said overlapping shoulders.

2. A hinged last, having its forepart and heel-part connected by a deep hinge-plate set vertically in the contiguous Walls of said last parts, said hinge-plate having a wide vertical engagement within the forepart substantially commensurate with the bulging portion of the forepart having large transverse width, and a heavy pivot in extending through the lower part of the forepart and the lower forward corner of said hingelate, whereby the twisting strains of the eel-part are transmitted by said hinge-plate 7 above the lower heel-part pin and said pivot pin and below the up er heel-part pin, and a gap between said hee -part and forepart extending upwardly from the front normally contacting ends of said overlapping shoulders, the walls of said gap having a forward dive'rgent curvature from their meeting ends atsaid front end of said overlapping shoulders, and the line of cut from the rear end of said 10 overlapping shoulders extending obliquely downwardly and rearwardly to the bottom CHARLES F. PYM.

Witnesses:

OTTo F. BARTHEL, CLEMENT R. STIOKNEY.

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