US2577243A

US2577243A - Heating device

Info

Publication number: US2577243A
Application number: US67452A
Authority: US
Inventors: Gunther Torsten Ragnar
Original assignee: FRITZ LUNDBERGS SKINNBEREDERI
Current assignee: FRITZ LUNDBERGS SKINNBEREDERI; Fritz Lundbergs Skinnberederi & Fargeri AB
Priority date: 1948-01-13
Filing date: 1948-12-27
Publication date: 1951-12-04
Anticipated expiration: 1968-12-04

Description

Dec. 4, 1951 T. R. GNTHER 2,577,243

HEATING DEVICE Filed Dec. 27, 1948 lllllllllillllllllll||l 7f Patented Dec. 4, 1951 Torsten Ragnar Gnthe signor to Fritz Lundber r, Tranas, Sweden, asgs Skinnberederi & Fargeri Aktiebolag, Tranas, Sweden, a corporation of Sweden Application December 27, 1948, Serial No. 67,452 In Sweden January 13, 1948 (Cl. 21S- 19) 2 Claims.

The present invention relates to electric heating devices, `and particularly to such as are adapted to heat rotatable rolls of ironing machines.

One object of my invention is to make provision for a more rapid heating of a hollow cylindrical ironing roll than has hitherto been possible with rolls having electric heating-elements contacting the inner peripherie-al surface of the roll.

Another object of my invention is to prevent over-heating and consequent damaging of the heating-resistors of heating elements for an ironing roll of the kind mentioned due to the comparatively slow heat transfer associated with such rolls having electric heating elements contacting the inner peripherical surface of the roll.

Another object of my invention is to make provision in heating devices for hollow cylindrical ironing rolls, for permitting thermal extension and contraction of the heating-resistors thereof in order to ascertain a longer life of the latter than has hitherto been possible with xed heating-resistors.

Other objects and advantages of my invention will be set forth hereinafter, reference being had to the accompanying diagrammatic drawing in which:

Fig. 1 is a side-view of an ironer in accordance with my invention;

Fig. 2 is a cross-section on the line II-II in Fig. 1; and

Fig. 3 is a side-view of a resistance-helix associated with an insulation-tube in accordance with this invention.

In the conventional heating-arrangement for the hollow cylindrical roll of an ironing machine for fur, the heating is accomplished by means of heating-elements contacting the inner surface of the roll. On account of the comparatively low rate of heat transfer from such elements to the roll, the heating-resistors of such elements are liable to be overheated and thus burnt down. Another disadvantage involved in such elements consists in that the heating-resistors are xedly positioned whereby no thermal expansion and contraction is permitted. This is a matter of great importance for the durability of the heating-resistors.

The disadvantages indicated, according to the present invention, are avoided by disposing electric resistance-helices 4 (see Fig. 3) inserted in insulation-tubes 5 in longitudinal bores 3 (see Fig. 2) provided in the roll I. For facilitating a larger scale along the electric connection of either the heating-resistors 4 mutually with each other, or with the source of current S (see Fig. 1), it may be convenient to attach the ends (2) of the resistancehelices (4) to insulating plates 9 perpendicular to the axis of the roll I and consisting of any suitable heat-resisting material, and provided with contact elements such as slip-rings I0 cooperating with brushes I I (Fig. l).

The invention, of course, should not be considered to be limited to the embodiment described and illustrated, as it is believed to be applicable to any kind of rotatable rolls required to be electrically heated.

What I claim and desire to secure by Letters Patent is:

l. A rotatable roll having an electric heating device, the peripheral portion of said roll having longitudinally extending bores therethrough, a heating resistor in the form of a helix, insulation tubes surrounding said resistor and said resistor having an external diameter less than the internal diameter of the insulation therearound whereby thermal expansion and contraction of the helices is possible, said insulated heating resistors being inserted in each said bore, said heating resistors being entirely surrounded by and embedded in the material of said roll to be heated. insulating plates arranged externally of said roll and perpendicular to the axis thereof, slip rings constituting contact elements on said insulating plates, the ends of the heating resistors being connected to said contact elements on said insulating plates, and brushes for cooperation with said contact elements for connecting the heating resistors to a source of current.

2. A rotatable roll having an electric heating device, the peripheral portion of said roll having a plurality of longitudinally extending bores therethrough, insulating tubes inserted in said bores, a heating resistor in the form of a helix slidingly disposed in each said tube in said bores, said resistors having an external diameter less than the intern-al diameter of the insulating tubes whereby said resistors are enabled to change their length upon heating and cooling thereof without obstruction to such movements in said insulating tubes, said tubes being entirely surrounded by the material of the roll to be heated.

TonsTEN RAGNAR GNTHER.

(References on following page) REFERENCES CITED The following references are of record in the Number le of this patent: 158,764 UNITED STATES PATENTS 5 Number Name Date 562867 415,856 Carpenter Nov. 26, 1889 665,388 Benner Jan. 1, 1901 1,492,540 Karcher et a1. Apr. 29, 1924 10 FOREIGN PAIEN TS Country Date Switzerland Feb. 1, 1933 France Mar. 5, 1887 vFrance Mar.- 23, 1914 Great Britain July 19, 1941l