US2012335A - Machine for applying intense heat - Google Patents

Description

7, 1935. M. J. BERGEN 2,012,335

MACHINE FOR APPLYING INTENSE HEAT Filed Dec. 22, 1955 a mmm Patented Aug. 27, 1935 MAOHINE FOB APPLYING INTENSE HEAT Martin J. Berge West Newbury, Mass., assignor Machinery Corporation, Pater- .son, N. 1., a corporation of New Jersey Aiil lication December 22, 1933, Serial No. 703,597

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This invention relates to machines having tools which are maintained at high temperatures and states'lietters Patent No. 'l,464,504,granted August I4, 1923, on an application flied in the 'nameoiJosephl 'ossa.

In machines of this kind, a piece of upper leather'is fed past an intensely hot tool which traverses the margin on one side of the piece to shrink and sear one side whereby the unshrunken side curls toward the shrunken side. The tool used for this operation commonly consists of a generally U-shaped member of suitable metal,

such for example as the alloy known as nichrome,-heaied to the desired temperature by an electric current. The temperature necessary to be maintained is very high, being always in the neighborhood of 2000 F. and being in many instances maintained at a higher temperature depending upon the nature of the leather which is being operated upon. At this temperature the tool is liable to bend if any considerable force is exerted upon it, and oxidation of the tool takes place which not only weakens the tool but causes its surface to become rough so that the useful life of the tool is comparatively short.

According to the present invention a machine, such for example as the one described above which is used to apply an intense heat to a piece of work, is provided with a tool consisting of a strong, rigid sheath or holder of suitable shape made of a rigid non-oxidizable material in which is enclosed a metallic heating element, the construction being such that the sheath forms the work-engaging portion of the tool and prevents access of air to the heating element. In the illustrated embodiment of the invention in which a shrinking tool is shown, the lower portion of a U-shaped conductor or heating element is enclosed in a sheath of fused quartz, the upper ends of the conductor being enclosed by and fastened in the terminals of an electric circuit.

Referring to the accompanying drawing,

Fig. l is an elevation of the work-engaging parts of an edge-finishing machine in which the present invention is embodied, a piece of work being shown in process of being operated upon;

Fig. 2 is a perspective of some of the same parts shown in Fig. 1 and also of a portion of the hammer;

Fig. 3 is an elevation of the tool with certain parts broken away;

Fig. 4 is a front elevation of a modified form of a tool; and

Fig. 5 is a side elevation of the tool shown in Fig. 4.

The machine, except for the construction of "-"g the shrinking tool, is or may be substantially the same as that of the machine of the patent identitled above and will therefore be but briefly described, reference being made to the patent for details of construction. The machine comprises lb a work support 5, a presser wheel I, a pair of feed members 9, I I which grip and feed the work I intermittently, a plow I3 for turning up the margin of the work, a shrinking tool indicated as a whole at A for applying an intense heat to i; the margin of the work to shrink and sear it so as to produce a small upstanding fin 200 on the work, and a hammer l which bends the fin more or less over the body portion of the work and aids in rounding the edge of the work. It will be understood that the work I00 is fed away from the observer as viewed in Fig. l or toward the observer as viewed in Fig. 2, to cause the margin and part of the edge of the work to be traversed by the shrinking tool and subsequently pounded by the hammer.

Hitherto the shrinking tool has been a metallic member, for example a piece of ni-chrome wire rectangular in cross-section, with the legs of the U clamped in a holder, a current of electricity being passed through the tool to raise it to a high temperature. Owing to this high temperature and the exposure of the work-engaging part of the tool to the atmosphere, two undesirable results occur. First, the rigidity of the tool is decreased with the result that the continual crowding of the upturned margin of the work between the plow and the tool tends to bend the work-engaging part of the tool away from the plow; and second, oxidation of the tool, in addition to weakening it, causes it to become pitted. Either the bending of the tool or the roughening of its work-engaging surface by pitting necessitates replacement of the tool, the bending because this causes an increase in the space between the tool and the plow so that the up-turned fin becomes thicker than it should be, and the pitting because the tool then exerts such a drag upon the work that it tends to stretch the edge thereof, with the result that the finished work has a wavy edge. A third disadvantage also occurs at times in that a rough coating forms on the surface of the tool. The exact nature of this coating is not known but its formation is apparently due to the fact that alum 55 is used in the tanning of certain light-colored leathers. Whatever the coating may be, it soon destroys the usefulness of the tool which must then be replaced.

To obviate these disadvantages, the tool of the present invention comprises a properly shaped sheath of a non-oxidizable material which retains its rigidity under intense heat, does not become pitted, and is not subject to the formation of'the coating referred to above. Inside the sheath is a metallic conductor, preferably of nichrome or some similar alloy. In the construction shown in Figs. 1 and 3, the sheath is a U- shaped tube I! of fused quartz through which passes a heating element [8 made of stranded ni-chrome wire. The legs of the quartz tube are received in socketed members I9, said members having threaded nipples I I9 at their upper ends. The upper ends of the strands of the wire I8 are spread out; and these spread-out ends are clamped to the tops of the nipples by clamping members 2| which are threaded on the nipples, the..clamping members 2| terminating at their upper ends in flat-sided stems I21 which are received' in suitable sockets in the tool holder of the machine and fastened in place by the usual screws.

In Figs. 4 and 5, there is shown a modified form of tool which makes use neither of a tube nor of. a stranded wire. The-heating element 3| is a single U-shaped piece of metal which may be substantially identical with the old form of shrinking tool; and the sheath comprises two plates of fused quartz 33, 35, having formed in one or both of their contacting faces a generally U-shaped channel to receive the element 3 I, said plates being detachably fastened together by small bolts 31 and lock washers 4| to permit the heating element to be readily removed and replaced.

The coefiicient of expansion of fused quartz is so small as to be practically negligible, but the coefiicient of expansion of ni-chrome is appreciable; and consequently the cross-section of the passageway in the sheath, whatever may be the form of the sheath, is slightly larger than the cross-section of the heating element. It should be particularly noted that the sheath is the work-engaging part of the tool, that the sheath is rigid and non-oxidizable so that it neither bends nor becomes pitted, and that whatever substances exude from the heated leather will not cling to its smooth surface.

Although the invention has been set forth as embodied in a particular machine, it should be understood that the invention is not limited in the scope of its application to the particular machine which has been shown and described.

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

l. A tool for applying heat to a piece of work comprising a bent tube of fused quartz, a stranded metallic heating element extending through and having its ends projecting from thetube, apertured nipples surrounding part of the length of said projecting ends, said nipples each having a threaded portion surrounding said end, and means for fastening the spread-out strands of the projecting ends of the element to said nipples comprising internally threaded caps having stems adapted to be secured to the terminals of an electric circuit.

2. A tool for applying heat to a piece of work comprising a plurality of plates of preformed fused quartz having channels and detachably fastened together, there being a channel in one or both of the contacting faces of the plates, and a heating element located in the channel.

MARTIN J. BERGEN.

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