US2375153A - Cushion heel - Google Patents

Description

May l, 1945- E. c UHLIG 2,375,153,l

CUSHION HEEL Filed Sept. 12, 1942 Er-ffy. 2

A./z 2f 2A y XQXMM Y is? "/4 25 W ATTORNEY Patented May l, 1945 CUSHION HEEL Applicationseptember 12, 1942,-Serial No. 458,097

1 Claim. (Cl. 36-35) This invention relates to cushion heels and more particularly to the type of cushion heel that has embedded therein arelatively rigid core or insert forming the nail-holdingl member.

It has been proposed heretofore to make' rubber heels having a core of. plywood or other relatively rigid material embedded therein to form the nail-holding member. These prior heels have had the relatively rigid core disposed at the attaching face of the heel so that the core formed a part of the attaching face and rested against the portion of the shoe to which the rubber heel. was secured.

These heels as constructed heretofore have not been entirely satisfactory due to the tendency of the core of plywood or other relatively rigid material to pull loose from the vulcanized rubber heel member when the heel is worn upon a shoe.

The present invention contemplates a construction whereby the relatively rigid nail-receiving core is much more securely attached to the resilient heel member than heretofore.

As a result of the construction of the present invention the likelihood of the core being pulled loose from the. resilient heel member is greatly reduced, and a heel of increased cushioning effect is secured.

The type oi heel above described as employed heretofore was molded in a heel vulcanizing mold of well known construction and comprising a metal member having formed therein a wellor cavity adapted to receive the rubber blank ofv vulcanizable stock. The bottom or floor of such well was constructed to impart the desired shape to the attaching face of the rubber heel, and the mold had a top plate adapted to be subjected to pressure to `cause the rubber blank to conform accurately to the interior of the mold duringv the vulcanizing period.

Heretofore it was the general practice to place the abovementioned core within the well of the mold `iust described so that this core would rest directly on the oor of the mold. This caused the outer face of the core to be disposed at the attaching face of the heel, and allowed almost no opportunity for the rubber in the mold to flow around the edge of the core and over its outer marginal edge thereof. Asa result, in such prior construction, the bond between the inner face of the core or insert and rubber heel member was relied upon almost entirely to anchor one to the other. This bond frequently proved insufficient to prevent' the core fromlbeing torn particularly weak fat the forward corners of the core'and along the' breast portion of the heel.

This difliculty of the prior construction is overcome by the present invention through a construction whereby the core is embedded Within the heel forming material at some distance from the attaching face of the heel so that a substantial amount of rubber overlies the outer face of the core around its marginal 'edge to help secure the core in place.

Thepresent construction serves also to form a distinct well in the attaching face of the heel and having the core disposed at the bottom of the well. As a result of this construction the core does not rest directly against the portion of the shoe to which the heel is attached as heretofore, but the core is held slightly spaced from such portion of the shoe by the rubber that extends over its marginal edge. This permits slight relative movement betweenl the core and shoe, whereby an increased cushioning action` is secured.

The novel construction of the present invention may be readily formed by employing a heel vulcanizing mold similar to thatv above described as employed heretofore, except that in carrying out the present invention it is necessary to provide such heel mold with a raised block or platform secured to the abovementioned floor at the i bottom of the cavity in the mold. The purpose of this block or platform is to hold the core in spaced relationto such oor during the molding and vulcanizing operation so that the pressure applied to the rubber blank by` exerting pressure upon the mold top plate will cause the vulcanizable rubber to ow around the core and over the marginal portion of its outer face, to

thereby cause a substantial amount of rubber to overlie this marginal edge portion of the core;

The contour'of the side walls of the raised block` serves to determine the shape of the walls of the well. That is, this block will serve as a mold for the well that extends inwardly from the ing description .when read in connection with` away from the vulcanized rubber, the bond being attaching face of the heel.

The various features of the present invention will be more fully understood from the followthe accompanying .drawingv illustrating two good practical embodiments of the present invention.

f In the drawing:

Fig. l is a plan'view of the attaching face of a cushion heel constructed in accordance withv the present invention.

Fig. `2 is a sectional view taken on the line 2 2 of'Fig. 1. y

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 1.

Fig. liis a longitudinal sectional View through a heel vulcanizing mold ,constructed to produce a heel in accordance with the present invention, the parts being shown before the mold is closed.

Fig. 5 is a view similar to Fig. 4 showing the appearance of the parts when the mold is closed.

Fig. 6 is a perspective View of the finished heel produced in the mold of Fig. 5; and

Fig. 7 is alongitudinal sectional View through a modified type of heel constructed in accordance with the present invention.

The cushion heel of the present invention is of a type commonly referred to as a rubber heel,

in which the major portion thereof is formed of vulcanized rubber or rubber-like material, and may be designed for attachment to a boot or `shoe either as a whole heel, half heel or treadlift.

The nished heel constructed in accordance with the present invention is herein designated in its entirety by the numeral II). This heel has the usual curved breast II attaching face I2 which rests against a portion of the shoe when the heel is secured to a shoe, and the lower or wearing surface I3 which contacts the ground or floor when the shoe is worn. p

The heel Ic has embedded therein a core or insert I4 to form the nail-holding member. This core which may be made of plywood or other relatively rigid sheet material and is preferably heel-shaped in contour, may be the same ply wood core which has been extensively manufactured and sold heretofore. The core Ill is shown lll as having the usual holes I5 formed therein to heel member so that it lies upon and forms part of the attaching face I2, whereas in accordance with the present invention the core I4 is disposed Well below the attaching face I2 and is positioned at the bottom of the well having the walls I6, as best shown in Fig. 6.A In other words, cushion heels having a core embedded therein to lie upon the heel attaching face are old, but it is believed to be new to provide a heel having a core of nailholding material embedded therein and exposed at the attaching face of the heel but with the core disposed some distance from this face so that it lies at the bottom of a well formed in the attaching face of the heel.

The heel IB may readily be formed in the heel vulcanizing mold shown in Figs. 4 and 5, which mold differs only slightly in construction from the vulcanizing heel mold commonly used heretofore. This mold as shown comprises the usual metal body member I1 having the heel molding cavity I8 therein and at the bottom of which cavity is formed the oor I9 that is usually curved as shown to impart the desired curvature to the heel attaching face I 2. The body member I1 has associated therewith the mold top plate 20 of usual construction and adapted to close the cav ity I8 and to mold the wearing surface I3 of the heel.

Heretofore in constructing rubber heels having embedded therein a core of plywood or the like, the core has been placed in the mold so that it rests directly upon the` floor forming the bottom of the heel receiving cavity of the mold, and as a result of such construction there has been very little opportunity for the vulcanizable rubber to flow around the outer edge of the core and over the outer marginal edge thereof to more firmly anchor the core to the vulcanized rubber.

In accordance with the present invention the mold shown in Figs. 4 and 5 is provided with a raised block or platform 2I that extends upwardly a short distance from the curved floor IQ. This platform is somewhat smaller in surface area than the core I4 as will be apparent from the drawing and the purpose of the platform 2I is to hold the core I4 in a raised position within the mold throughout the heel forming operation. That is the platform 2i holds the core I4 surbciently spaced from the floor I9 to permit a substantial amount of the vulcanizable rubber to flow around the outer edge of the core I4 and over its outer peripheral edge to thereby provide a covering rim 22 of substantial thickness, and which serves to hold the core very firmly in place. This rim also holds the core I 4 slightly spaced from the portion of the shoe to which the heel is nailed.

The pins 23 within the mold enter the holes iof the core to position the core accurately in the mold upon the. platform 2i, and the Vertical walls of this platform impart a corresponding shape to the side walls of the Well I6.

In carrying out the present invention the core I4 is placed within the vulcanizing mold on the platform ZI as above described, whereupon the blank 24 of rubber or other vulcanizable material is placed in the mold in the position in which it is shown in Fig. 4. The mold may then be closed by hydraulically forcing the top plate 20 against the upper face of the body member I 'I as shown in Fig. 5, to thereby subject the rubber blank 2li to sufiicient pressure to cause it to conform accurately to the interior of the mold. This will cause the vulcanizable rubber to completely surround so much of the edge portion of the core I4 as projects beyond the supporting platform 2| and to accumulate over the edges of the platform 2l to form the rim 22, and around the sides of the platform to form the well It as will be apparent from Fig. 5.

The portion of the core Ill which is disposed near the curved rear wall of the heel is preferably beveled as at 25, so that the amount of rubber at this portion of the heel where it wears away rapidly may be increased. The amount of rubber in this area of the heel may be further increased, in accordance with the present invention, by forming the platform 2l so that the beveled portion 25 of the core I4 will project a substantial distance beyond the platform as shown in Fig. 4. As a result of this construction the severepressure which the compressed rubber exerts upon the portion 25 of the core will bend this portion downwardly as shown in Fig. 5, so that the heat and pressure to which the mold is subjected during the rubber vulcanizing period will cause this flexed portion of the core to take a permanent set in this new position as indicated by '26.

In some cases it may not be desirable to flex the rear portion of the core I as at 26 in which case the platform 2l should be made wider in this area than shown in Fig. 5 so that the core will not4 extend so far beyond the platform. This will support the core sufficiently to prevent it from being fiexed at any point and as a result the modied construction of Fig. 7 will be produced wherein it will be noted that no portion of the core I4 is flexed.

It will be seen from the foregoing that heels vith a heel-shaped core of hard stiff material embedded therein so that lthe major portion of one face of the core is exposed but the outer marginal portion of this face entirely around the core is covered by a lip of such resilient material oi appreciable thickness to hold'the core firmly in place, and thereby form a Well of con siderable less depth than the thickness of the core vin the face of the heel and which has a Well 10 wall entirely around the heel.

EDWIN C. UHLIG.

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