US2816374A

US2816374A - Dowels for use in heel blocks and the like

Info

Publication number: US2816374A
Application number: US544498A
Authority: US
Inventors: Jr Edgar E Joiner
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1955-11-02
Filing date: 1955-11-02
Publication date: 1957-12-17
Anticipated expiration: 1974-12-17

Description

Dec. 17, 1957 E. E. JOINER, JR

I DOWELS FOR USE IN HEEL BLOCKS AND THE LIKE til/00d Fig. 2

Filed Nov. 2, 1955 In yen for Y 24 or Joiner; Jr. his Affomey United States Patent DOWELS FOR USE IN HEEL BLOCKS AND THE LIKE Edgar E. Joiner, Jr., Andover, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application November 2, 1955, Serial No. 544,498

6 Claims. (Cl. 36-34) The present invention relates to dowels for use in the reinforcing of wood heel blocks and accordingly finished heels made from said blocks, it being an object of the invention to provide an improved dowel which can be produced cheaply and can be incorporated in heel blocks quickly and effectively by machines now used for that purpose and which greatly strengthens the blocks as well as permits the blocks to be regraded with present equipment and to be effectively attached to shoes and to have top lifts attached to them without any danger of the blocks being split.

Since the advent of wood heels many different types of dowels, which are driven into bores formed in tread end faces of wood heel blocks from which the heels are made, have been proposed for strengthening said heels. Until recently, however, it has been almost universal practice to employ the usual solid steel dowels and the solid wood dowels because of the expense and the various practical drawbacks in the various proposed dowels. Solid wood dowels do not adequately strengthen the heels and solid steel dowels, although satisfactory from a standpoint of strength, have certain disadvantages, for example, the dowel cannot be extended into close proximity to the tread or lower end face of the heel without damaging the saw during the regrading of the heel. Moreover, if the steel dowel does extend into close proximity to the tread end face of the heel, top lift attaching nails driven into the heel are deflected by the dowel causing the lower end of the heel to be split and if the dowel does not extend into close proximity to the lower end of the heel the unfilled bore at the lower end of the heel weakens the heel and reduces the amount of material into which the heel attaching nails can be driven or anchored. Furthermore, steel dowels cannot be driven centrally heightwise into the heel block because they interfere with the driving of fastenings used in the attachment to the shoe of the heel made from the heel block, it being well known that a fastening such as a screw or nail, driven through the heel seat of the shoe and into the heel into deflecting relation with the solid steel dowel, will cause the upper end of the heel to be cracked.

With the above object in view and in accordance with a feature of the present invention I have provided a dowel which is adapted to be driven as a unit into a heel block for reinforcing said block, said dowel comprising a compressible non-metallic core having a thin metallic jacket wrapped substantially around and embedded substantially its full thickness into one portion of a peripheral face of the core and substantially flush with an adjacent portion of said peripheral face, said metallic jacket being spaced by said adjacent portion from one end of the core.

In practice the core of the present dowel is made of wood and has a lengthwise central portion thereof substantially surrounded by a thin steel jacket terminating short of opposite ends of the core, that portion of the core surrounded by the jacket being compressed by the jacket whereby the diameter of the jacketed portion of the dowel is approximately the same as that of the unjacketed 2,816,374 Patented Dec. 17, 1957 end portions of the dowel. The diameter of the dowel is substantially the same as the diameter of the cylindrical bore formed in the tread end of the wood heel block, said dowel being driven under heavy pressure into the bore with its leading end forced against an inner end face of the bore and with its trailing end driven substantially flush with the tread end face of the graded heel block.

The diameter of the present wood core, steel jacketed dowel is only slightly greater than the diameter of the commonly used solid steel dowel and although considerably weaker as a dowel, per se, when subjected to bending and shearing stresses, than the solid steel dowel, the present dowel incorporated in the heel block produces a block and accordingly a heel which has at least as much resistance to breaking under bending and shearing stresses as a corresponding heel in which the solid steel dowel is incorporated. It has been found that when the illustrated dowel has been driven under heavy pressure into the bore formed in the heel block, the wood core is compressed lengthwise and expands laterally and thus imparts to the steel jacket which slides with a minimum of friction in the bore of the block, a heavy force acting laterally against the wall of the bore, thereby preloading the heel block and thus greatly increasing the resistance of the heel to breaking under bending and shearing stresses.

The upper and lower end portions of the cylindrical bore formed in the heel block have force-fitted into them the unjacketed end portions of the wood core and accordingly the lower end of the heel block may be regraded by the usual woodworking saws without damage to the saws and also consists of a solid mass of reinforced wood to which the original and replacement top lifts may be quickly and effectively attached, the upper end of the heel made from the block being adapted to receive a center heel attaching screw and toed-in nails which surround said screw and are used in the attachment of the heel to the shoe without engaging the jacket of the dowel driven into the heel.

The present invention consists in the above and hereinafter described novel features, reference being had to the accompanying drawings, which illustrate one embodiment of the invention, selected for purposes of illustration, said invention being fully disclosed in the following description and claims.

In the accompanying drawings:

Fig. 1 is a vertical longitudinal median section through a Louis wood heel block into a bore of which an illustrative dowel has been driven;

Fig. 2 is a section on the line II-II of Fig. 1;

Fig. 3 is an enlarged perspective view of the dowel;

Fig. 4 shows, partly in side elevation and partly in vertical longitudinal median section, a rear end portion of a shoe to which is attached a Louis heel made from the wood heel block shown in Figs. 1 and 2; and

Fig. 5 is a bottom view of a top lift of the heel shown in Fig. 4, the dowel of the heel being shown in outline.

An illustrative dowel 10 is described with reference to its incorporation in a Louis wood heel block 12 which has an attaching face 14 and a tread end face 16 in which is formed a cylindrical recess or bore 18 extending generally heightwise of the block and terminating at an inner end face 20 arranged in close proximity to the attaching face. In the illustrative heel block 12 the end face 20 of the bore 18 is shown as approximately A" from the attaching face 14 of the block but if desirable to strengthen the heel block, said end face may be in closer proximity to said attaching face.

The tread end face 16 of the wood heel block 12 is formed during the grading of the block at the wood heel factory, the dowel 10 being subsequently driven as a unit into the bore 18 until a leading or inner end thereof is forced against the inner end face 20 of the bore, the

dowel preferably being of suitable length to insure that its outer or trailing end face shall be in approximate alinement with the tread end face 16 of the wood heel block. A wood heel 17 which is a given size and style and is formed from the block 12 is made to accommodate a shoe 19 which may be any one of several different sizes and/or styles and has its block regraded for the particular shoe to which it is to be attached at either the wood heel covering factory or at the shoe factory, the already graded wood heel block 12, forexample, being regraded along a line AA.

After the heel block 12 has been regraded it is common practice to attach a top lift 22 to a regraded tread end face 24 of the heel block 12 by a plurality of nails 26 which are commonly referred to as slugs and are about /2 long, headless, and are driven in toed-in relation through the top lift and into the lower end of the block. In a heel block 12 having a fairly small top lift 22, such as illustrated herein, three nails are commonly used although it is also the practice to attach the top lift to the heel by more than three nails. When the heel block 12 has had a cover 28 applied to it, it may be said to constitute a completed heel 17 and is attached to the shoe 19 by a screw 32 and toed-in nails 34 which are driven through the heel seat of the shoe and into the heel block. After the attachment of the heel 17 to the shoe, the breast of the heel has a covering flap 35 applied to it and the heel, except for various finishing operations. becomes a finished heel. When the wood heel block 12 is essentially finished it is commonly referred to as a heel these two terms being used synonymously when the block has acquired the general shape of a heel.

The dowel comprises a wood or nonmetallic core 38 which is slightly greater than the diameter of and longer than a corresponding steel dowel (not shown) and which has wrapped substantially around and pressed into a median lengthwise portion thereof a thin steel jacket or sleeve 40 of substantial length. Opposite ends of the jacket 40 are spaced from and accordingly terminate short of the ends of the core 38 and the end unjacketed or exposed portions 42 of the dowel, formed by the portions of the core extending beyond the jacket, have a diameter which is substantially equal to but may be very slightly smaller than the diameter of the major portion of the jacket. The portion of the core 38 surrounded by the jacket 40 may be said to be compressed whereby the diameter of the jacketed portion of the dowel 10 is substantially the same as that of the unjacketed end portions 42 of the dowel.

One form of dowel 10 which has been found to be satisfactory has a core 38 the unjacketed end portions 42 of which are substantially .1875 in diameter and are adapted to be force-fitted into the bore 18 which is also substantially .1875" in diameter, the steel jacket 40 having a thickness of between .008 and .013 and, when it is wrapped about and pressed into the wood core, having, except for crimped end portions hereinafter referred to, a diameter varying between .189" and .191. In order to insure that the opposite end portions of the jacket 40 shall be pressed just below the peripheral faces of the unjacketed end portions 42 of the core 38, said end portions of the jacket, as they are wrapped around and pressed into the core, are operated upon by crimping mechanism. By crimping the opposite end portions of the jacket 40 into the wood core 38 to diameters of approximately .185 the dowel may be effectively driven into the wood heel block without the danger of the core sliding with relation to the jacket.

The dowels 10 are made in various lengths to accommodate heel blocks 12 of different heights, the jackets 40 of dowels of different lengths being approximately the same length which is in the vicinity of 1 /2", such length being sufficient to extend through the critical shank portion of the heel which is likely to be fractured transversely by shearing. It will be noted in connection with tion of the heel is subjected to a heavy stress applied transversely thereto, said shank portion is likely to become fractured. The core 38 of the dowel 10, as is common in wood dowels, has its grain extending lengthwise of the dowel and heightwise of the heel block 12 in which the dowel is incorporated.

Dowels 10 of different lengths may be readily identified by enamelling the cores 38 of the dowels different colors whereby to determine, after the dowels have been driven into the heel blocks 12 the approximate distances between the ends of the dowels and adjacent ends of the jackets 40, respectively, of the dowels. By noting the color of the core 38 of the dowel 10 driven into the heel block 12 the operator, who is regrading the heel block, can readily insure himself that a saw, commonly used during regrading the heel block, shall not be en countered by the steel jacket 40 of the dowel. The lengths of the dowels 10 used in the heel blocks 12 are such that when the dowels are fully driven into the graded blocks with their inner ends forced against the inner end faces 20 of the bores of the blocks, the outer ends of the dowels will be approximately flush with the tread ends 16 of the blocks. When the heel block 12 is regraded it is trimmed as above explained across the lower unjacketed end portion 38 of the dowel 10 along the line A--A, thus trimming the dowel flush with the regraded end face 24 of the heel block.

When the jacket 40 has been wrapped substantially around and pressed into the cylindrical wood core 38 the entire outside surfaces of the dowel 10 are coated with hard wax so that the dowel shall be moisture-proof and to insure that the diameter of the dowel shall remain substantially constant to facilitate its being driven into the bore 18 of the heel block as above described. When the dowel 10 has been force-fitted into the bore 18 of the heel block 12 the outer unjacketed end portion 42 of the core 38 of the dowel is in forced relation with the lower end portions of the wall of the bore 18 of the dowel and in effect forms with the main body of the heel block a solid base portion adapted effectively to receive the medin nails 26 used in the attachment of the top lift 22 to the heel block. As above explained the dowell 10 extends into close proximity to the attaching face 14 of the heel block 12 and in high heels the upper unjacketed end portion 42 of the core 38 is force fitted into the upper end portion of the bore 18, thus allowing the commonly used heel attaching screw 32 and nails 34, which are driven through the heel seat of the shoe and into the heel, to be driven without interference into the heel. If desirable the completed dowels 10 may be coated with lacquer. During the dowel driving operation the lacquer is softened by heat generated during the driving operation and when the dowel cools it is bonded in the heel by the lacquer.

As above explained, by driving the dowel 10 under heavy pressure into the bore 18 formed in the heel block 12, the wood core 38 of the dowel is compressed length wise and expands laterally thus imparting to the wall of the bore a heavy force which preloads the heel block so that a shock imparted to the heel 17 formed from said block will momentarily introduce a slight deflection in the dowel which serves to distribute the shock and thus causes the heel to absorb said shock. By providing a steel jacket 40 of the above-mentioned thickness it has been found that the jacket will not prevent expansion of the wood core 38, which is subjected to the driving force, as the dowel is incorporated into the wood heel block. It will be understood that various metals or alloys may be used in place of steel in the forming of the jacket 40 in which event the thickness of the metal will depend upon the modulus of elasticity of the particular metal or alloy with respect to steel.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A dowel which is adapted to be driven as a unit into a heel block for reinforcing said block comprising a readily compressible nonmetallic core having a thin metallic jacket substantially surrounding and embedded its full thickness into one portion of a peripheral face of the core with an outer face of the jacket in substantially flush relation with an adjacent unjacketed portion of said peripheral face, said metallic jacket being spaced by said adjacent unjacketed portion from one end of the core.

2. A dowel which is adapted to be driven as a unit into a heel block for reinforcing said block comprising a readily compressible nonmetallic core having a thin metallic jacket substantially surrounding and embedded its full thickness into a lengthwise median portion of a peripheral face of the core with an outer face of the jacket in substantially flush relation with adjacent unjacketed portions of said peripheral face, said metallic jacket being spaced by said adjacent unjacketed portions, respectively, from opposite ends of the core.

3. A dowel which is adapted to be driven as a unit into a heel block comprising a cylindrical wood core, and a thin metallic jacket which substantially surrounds and is embedded substantially its full thickness into one lengthwise peripheral portion of the core and is also spaced from one end of the core thus leaving an end portion of the core exposed, said jacket having a diameter approximately equal to the diameter of the exposed end portion of the core.

4. A dowel which is adapted to be driven as a unit into a heel block for reinforcing said block comprising a cylindrical wood core, and a metallic jacket which substantially surrounds and which is embedded substantially its full thickness into a lengthwise median portion of the core and is spaced from the opposite ends of the core leaving exposed end portions of the core at opposite ends of the jacket, said jacket having a diameter approximately the same as that of the exposed opposite end portions of the core.

5. A dowel which is adapted to be driven as a unit into a heel block for reinforcing said block comprising a cylindrical wood core, a metallic jacket which substantially surrounds a lengthwise median portion of the core and is embedded substantially its full thickness into said core and which has its opposite ends crimped to a depth slightly greater than the full thickness of the jacket into the core and is spaced from the ends, respectively, of the core leaving exposed end portions of the core, the uncrimped portions of said metallic jacket having a diameter substantially equal to the diameters of the exposed end portions of the core.

6. A dowel which is adapted to be driven as a unit into a heel block for reinforcing said block comprising a cylindrical wood core and a metallic jacket which has a thickness between .008" and .013" and which substantially surrounds and is embedded substantially its full thickness into a lengthwise median portion of the core and is spaced from the opposite ends of the core leaving exposed end portions of the core at opposite ends of the jacket, said jacket having a diameter approximately the same as that of the exposed opposite end portions of the core.

References Cited in the file of this patent UNITED STATES PATENTS 1,356,861 George Oct. 26, 1920 1,494,955 Hauck May 20, 1924 1,724,610 McArthur Aug. 13, 1929 1,861,118 Gilowitz May 31, 1932 2,703,461 Fox Mar. 8, 1955 FOREIGN PATENTS 191,416 Great Britain Jan. 15, 1923