US3118240A

US3118240A - D hooge

Info

Publication number: US3118240A
Authority: US
Priority date: 1959-01-12
Filing date: 1960-01-04
Publication date: 1964-01-21
Anticipated expiration: 1981-01-21
Also published as: GB873881A; CH359679A; FR1235155A

Description

E. DHOOGE Jan. 21, 1964 CRADLE FOR IRONING MACHINES 2 Sheets-Sheet 1 Filed Jan. 4, 1960 FIG? INVENTOR ATTORNEYS Jan. 21, 1964 E. DHOOGE CRADLE FOR IRONING MACHINES 2 Sheets-Sheet 2 Filed Jan. 4, 1960 FIG: 3

INVENTOR BY x- 62 M ATTORNEYS United States Patent 3,118,248 CRADLE 1 0R RDNHIG MAQHENES Emile DHooge, Ghent, Belgium, assignor to Constructio- Werkhuizen Emile DHooge P.V,B.A., Lederberg-Ghent,

Belgium Filed Jan. 4, 196%), Ser. No. 38% Claims priority, application Belgium Jan. 12, 1959 1 Claim. (Cl. 38-56) The term cradle for ironing machines is to be understood as meaning a trough in which a roller or ironing cylinder is rotated to iron various textile fabrics such as linen and the like placed therein.

Generally, these cradles are double walled vessels which enclose a chamber wherein a pre-heated fluid is circulated for bringing the smooth semi-cylindrical inner wall of the cradle to the optimum temperature needed for ironing the linen.

The main object of the present invention is to construct a cradle which is very light in construction, capable of expanding and contracting, uniformly when subjected to temperature changes, and designed to have a heating chamber of small volumetric capacity. The fluid which is most appropriate for transmitting heat is saturated steam. it has a large heat content and high coeflicient of transmission while at the same time having the added advantage that its temperature remains constant during condensation as long as the pressure is maintained constant. Consequently, in attaining the most desirable ironing temperature, a specific steam pressure is maintained. For ironing apparatus this pressure is about 8 kg./cm.

Another object of the invention consists in replacing the usual cast cradles of prior art constructions, by cradles fabricated from specially shaped steel plates joined by welding.

This feature is extremely important, as it is well known that prior art cradle construction by casting results in the cradle having both thick walls and the other disadvantages connected with casting processes.

Although cradles of welded construction are well known in prior art, they are usually constructed of heavy steel plates, which are first curved and then fitted together leaving a space between them in order to form a heating chamber. The edges of the outer plate are usually turned inward to contact the inner curved plate the plates being welded along the point of contact.

According to the instant invention however, the construction follows an altogether new design characterized by a multiple connection between the two plates, which makes it possible to use much thinner material than in the above-mentioned case or with the usual cast cradle.

For materializing this new design, adequately spaced inward bulges are embossed into the outer plate, before it is curved so that in appearance it resembles a hone comb. The bulges form a plurality of rows of supporting points in the outer plate which are subsequently attached to the inner plate, by electric arc welding. The edges of the outer plate have previously been turned inward and welded to the inner plate.

Tests have definitely shown that the distortions in the cradle are practically limited to the normal expansions which result from the temperature rise.

Hydraulic pressure tests imposed on the cradle, with pressures eight times higher than the pressure in service, have given rise to negligible distortions which are well within the limit of elasticity of the plates, so that the cradle, after the pressure is released, recovers its initial shape.

The addition of a separate channel for drawing off condensed steam does not interfere with cradle heating and ensures a 100% evacuation of the condensed steam.

A thorough ventilation on the top guarantees an ideal transferrence of heat by this device.

The shape, number and dimensions of the supporting bulges are functions of the particular ironing machine used, the type of fabric ironed and the amount of heating required during ironing. Thus, these characteristics of the bulges can be varied without limiting the intended scope of the invention.

By Way of example, and without involving any limitations whatever, a preferred embodiment of the invention is described in detail below with reference to the appended drawings of which:

FIGURE 1 is a diagrammatic cross-section showing the main parts of an ironing machine which lends itself to the application of those cradles which are the object of the present invention;

FIGURE 2 is a cross-section of the main elements of a prior art cradle;

FIGURE 3 is a cross-section of the main elements of an improved cradle according to the invention;

FIGURE 4 is a partial side view of the outer plate of the cradle shown in FiGURE 3.

A simplified and diagrammatic view of a complete ironing machine 1 is given in FIGURE 1 and shows two heated cradles 2 in each of which a cylinder or ironing drum 3 revolves about a horizontal shaft 4. In this particular instance, the cradles 2 are connected by means of a special bridge 5 which is illustrated in applicants Belgian Patent No. 538,181. This same figure also comprises diagrammatic representations of the following parts: the fabric lead-in 6 and the fabric lead-out 7, as well as the operating pedal 8 and the several other elements of which the machine is built-up.

The present invention is only concerned with the cradles 2.

In order to emphasize the characteristics of the cradle according to the present invention, in which the welding process is applied for joining two plates, FIGURE 2 shows a cross-section of a prior-art cradle which is also constructed by welding two plates together. In this known design, two fairly thick plates 9ltl are used; the inner plate 9 is of semi-cylindrical shape and its inner radius R is slightly larger than the outer radius R of the ironing drum, including the outer cover of the latter. The outer plate 1% is curved in such way that its radius of curvature is smaller than that of the inner plate 9, and the longitudinal edges ll-ll of the outer plate It} are turned inward in order to come into contact with the outer face of plate 9 to which they are fastened by means of a welded seam 1314.

In this way, a continuous heating chamber 15 of large capacity is produced. Such type of construction is however strongly subject to distortion under temperature change and therefore calls for the use of fairly strong plates 9ltl. As however, considerations of cost and of constructional difiiculties soon set a limit to the maximum strength of sheet steel which can be used, this kind of design results in a construction whose resistance to distortional stresses resulting from the important temperature changes, is questionable. Further, the capacity of the heating chamber 15 is comparatively large in comparison with the amount of heat transferred to the fabric.

According to the present invention, and as represented diagrammatically in FIGURES 3 and 4, the new construction is based on the use of an inner plate 16 of semicylindrical shape, the plate being of a much thinner material than that which is needed in the construction referred to above and represented in FIGURE 2. in practice, it can be stated that the thickness of the inner plate 16 is reduced with respect to that of the former inner plate inside the craters formed by aforesaid bulges 38.

9 in the ratio of 17 to 1G, which represents a reduction of roughly 40%.

As regards the outer plate 17, a still thinner plate is used with respect to the example given above, the ratio in this case being 15 to in other words, this plate is three times thinner, which represents a reduction of about 70%.

According to the present invention, this thin outer plate 17 is locally distorted in order to form a series of mutually perpendicular rows of bulges 18 extending over its whole area on the face which is intended to come into contact with the outer face or" the semi-cylindrical plate 16.

The plate 17 has substantially fiat portions 18:: located between the bulges 1 3, which are in the nature of depressions as viewed from without.

The longitudinal edges 19-2=1i of plate 17 are bent inward.

Plate 17 which has thus been prepared, is then curved in such way that it comes into contact with the outer face of the semicylindrical plate in to which it is fastened by applying electric arc Welding at the bottom of and This fastening is completed by welded seams 21-22 applied along the bent-over edges 19-23 of the outer plate in order to fasten these edges to the outer face of the semicylindrical plate 16.

As a result of the foregoing, a multi-cellular heating chamber 23 is obtained, in which all cells are intercommunic'ating, thus enabling a free circulation of the heating fluid through the whole free space enclosed between the aforesaid plates Hl7.

In the above construction, the capacity of the chamber is reduced to a bare minimum, as Well as the thickness of the plates used in the construction, thus the thermal efiiciency reaches a maximum and the resistance of the constructionis considerably higher than that of aforementioned constructions and more especially than that of the welded construction represented in FIGURE 2 A useful addition to this design can be made by applying along the lowest part of the outer plate 17, a condensed steam manifold consisting of a simple gutter 2.4, of semi-tubular cross-section welded to the plate and connected through a number of appropriate holes 25 with the heating chamber 23.

Obviously, the preferred form of embodiment described abcve is not limited in any way to the shape, the sizes, the numbers and the location of the bulges 18, since the configuration of these bulges can vary in an infinite number of ways, and all embodiments which are consequent thereon lie within the scope of the present invention.

At the same time, this invention extends to all thin, adequately shaped plates specially intended for use in this construction, to the cradles to which the features disclosed by the present application are applied, as well as to all machines equipped with such cradles. The latter can also be made in any sizes required by the machine to be equipped therewith.

What I claim is:

In a steam ironing machine, a cradle comprising a semi-cylindrically shaped inner plate having a smooth outer surface, a substantially semi-cylindrically shaped outer plate or" lesser thickness than said inner plate, said outer plate having inturned longitudinal edges firmly connected with the outer surface of the inner plate, said outer plate further having substantially fiat portions uniformly spaced from said outer surface of the inner plate and bulges located between said fiat portions, said bulges extending toward said inner plate and being firmly connected with said outer surface thereof, said bulges being uniformly spaced and located in mutually perpendicular longitudinal and transverse rows, the bulges of one row being alined with the bulges of the next row, whereby a uniformly disposed multi-cellular space is formed be tween said outer and inner plates, the cells of said multicellular space being interconnected, and a manifold connected to the lowermost portion of said outer plate and communicating with said multi-cellular space.

References Qited in the file of this patent UNITED STATES PATENTS 2,215,918 Fay Sept. 24, 1940 2,391,997 Noble Jan. 1, 1946 2,652,644 Howlett Sept. 22, 1953 FOREIGN PATENTS 743,991 Germany Ian. 6, 1944 446,507 Great Britain Apr. 27, 1936