US 1929742 A
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Oct. 10, 1933. R. v, HEDLUND FORMING FULLY ROUNDED CORNERS ON SHEET METAL FURNITURE Filed July 29, 1932 2 Sheets-Sheet 1 ATTORNEY Oct. 10, 1933. R. v. HEDLUND FORMING FULLY ROUNDED CORNERS ON SHEET METAL FURNITURE Filed July 29, 1932 2 Sheets-Sheet 2 ATTORNEY Patented 10,1933. 1
PATENT OFFICE FORMING FULLY ROUNDED CORNERS ON SHEET METAL FURNITURE My invention relates primarily to kitchen equipment such as tables, sinks and the like and more particularly to the formation of such articles when made of sheet metal. The relatively recent increase in general knowledge regarding the cleanliness necessary during the preparation and care of food has caused metal to replace wood in the construction of such equipment. A
non-corrodible metal, such as monel, is especially desirable for such purposes 'as it will also take a high degree of polish.
The top of av good wooden kitchen table is smoothed off at the edges and the corners rounded not only for appearance sake but more especially for safety against injury to the kitchen operative due to accidental contact. At first, a sheet metal table top was. formed with sharp corners constructed by cutting a piece of metal from each corner, bending adjacent edges at an angle to the surface until the cut metal edges came into contact and then welding them together. The rough spots were then ground ofi and polished, but the result was a mitred corner,
a sharp corner, which is far more dangerous to bump against than a corner of a wooden table.
Metal kitchen tables and sinks for restaurants, hospitals and hotels are apt to be relatively large, sized to supply the demands of the patrons and of a variety of shapes to provide an economy of floor space. Generally they are made to lit a certain spot in a room and it is seldom that two architects design two kitchens of the same size and shape. Therefore, such equipment cannot be made on a production basis but has to be built up by the processes possible with the tools of the tinsmith.
I have invented a new, novel and relatively inexpensive method of making fully rounded corners on a metal top table or a sink which adds to its beauty, renders it more easily cleanable and presents smoothly curved and relatively large areas for accidental contact, tending to diminish injury to both person and building. The appearance of such equipment also renders them more supported on a stiff frame, are made of non-- corrodible metal of approximately an eighth of an inch thickness and commonly the edges are formed or rolled to a curve cylindrical in shape and of a diameter of about two inches. This'calls for a cutting away of the metal at the corners before the edges are rolled and later welding in corners which have been formed to the required shape. My invention' is especially applicable to the requirements of such conditions.
easily salable. Such table tops, which are usually.
in the appearance shown in Figs. 2 and 3.
The making of a sink requires much the same procedure as does a table but with the addition of extra welded-in pieces for the bottom corners. Sinks for the kitchens of large institutions are long and often have to conform to the shape of 0 the room. Thus they are .specials and, of necessity, are made up by the tools of a well equipt tinsmith shop. I My invention allows smoothly rounded corners to be formed on such sinks thus adding materially to cleanliness and to the safety 5 from injury to the kitchen operatives.
The drawings illustrate he application of my invention to two types of corner.
Fig. 1 is a plan view of a table top showing the fully rounded corners;
Fig. 2 is a front elevation of Fig. 1, being partly broken away on line A-A;
Fig. 3 is a perspective view of a table top with the edges rolled over and ready for the welding-in of the segment of the spherical-like shell;
Fig. 4 is a full size plan view of the blank before being drawn to its spherical segment shape;
Fig. 5 is a perspective view of the piece shown in Fig. 4 after being drawn so that its surface becomes substantially spherical;
Fig. 6 is a plan view of the three blanks used to form the major portion of a sink;
Fig. 7 is an end elevation illustrating the first bends in the construction of a sink;
Fig. 8 is a perspective view of my method of constructing a sink and showing an end weldedin;
Fig. 9 is a plan view of the blank, before drawing, for the upper corner on the sink;
Fig. 10 is a plan view of the blank, before drawing, for the lower corner on the sink;
Fig. 11 is a perspective inside view of one of the end pieces for my sink, and
Fig. 12 is a perspective View of my sink showing the fully rounded corners.
The odd-shaped table top 1 shown in Fig. 1 is characteristic of the type often encountered in special work. After the proper-sized pieces have been cut out of the corners, the flat metal is rolled over in the well-known manner resulting I prefer to roll the edges over so that they terminate in a plane 2 parallel with the table top proper. A good way is to turn the lower edges under no further thanshown in Fig. 3, though by my improved method I can, if desired, carry the lower edges into the plane above referred to and as indicated at 3 in Fig. 2. To fill in the holes 4 at the corners I generally employ blanks 5 which are drawn under a press so that the surface of the blank becomes spherical, or substantially so, as shown at 6 in the perspective view Fig. 5. These spherical-like shells are then welded into the holes 4 at the corners, or attached in some other good manner and after the joints have been ground evenly and the metal polished the appearance is extremely pleasing to the eye as the joint is quite invisible with the seams eliminated. Such corners may then be characterized as comparable to the surface of revolution about a desired axis of the curved edges leading thereto.
It is obvious that by the use of my novel method I can carry two opposing edges around and underneath until they meet under the center of the table. When this joint is welded up and the corner pieces put in I would have a completely enclosed integral table top with fully rounded corners and a top and bottom consisting of smooth, plane surfaces.
One good method of forming the sink '7 shown in Fig. 12 is to cut out two end pieces 8 and 9 and body portion 10 which is then rolled and bent to the shape 11 shown in Fig. '1. The end pieces 8 and 9 are rolled so that each becomes as shown like 12 in Fig. 11 after which they are welded to the body portion as shown clearly in Fig. 8. If preferred, the inturned edges which appear on end pieces 12 in Fig. 11 may be omitted thereon, being formed instead on the main body portion 10. The sink is now complete except for filling in the holes 13 at the top corners and the smaller holes 14 at the bottom corners. I accomplish this by the same general idea as previously outlined in describing the table top, by utilizing blanks 15 and 16 of the proper shapes which will,
4 after drawing, be welded into holes 13 and 14 and present the, fully rounded edges so much desired onthis type of kitchen furniture.
It is well known that heavy forming and drawing presses are economical to use in quantity production. However, as the diameter of a rolled edge increases in proportion to the thickness of the metal from which it is made the difficulty of compressing the metal on the extreme inner edge of a curved corner, something similar to that shown at 3 in Fig. 2, constantly becomes more difficult, or even to approximate such shapes. On the other hand there is practically no limit to such sizes in my class of work, but I prefer to limit myself to a minimum diameter of the rolled edge of eight times the thickness of the metal in order that the edge may appear in proportion to the size of the furniture. The rolled over edge can be nearly a full cylinder or be less than a half cylinder, as desired, because of the use of my invention. It is apparent that my novel system herein set forth is especially well adapted for the tinsmith both as regards beauty, utility and economy in manufacture.
It is to be understood that the particular embodiments of the invention disclosed herein are of an illustrative character and are not restrictive, and that various changes in form, construction and arrangement of parts may be made within the spirit and scope of the following claims.
Having thus described the invention, what is claimed as n :w, and desired to be secured by Letters Patent, is:
1. The method of forming a fully rounded corner on a table top, sink or the like made from sheet metal and having its edges shaped to approximate sectors of cylinders which consists in. fitt'ng a sector of a substantially spherical shell into each corner and welding it in place whereby the contour of the corner becomes substantially thesurface of revolution about a desired axis of the contour of the cylindrical-like edge.
2. The method of forming a fully rounded corner on a table top, sink or the like-made from sheet metal and having rolled over edges compr. sing the step outlined in claim 1 together with smoothing off the rough places resulting from the fitting and welding and polishing the corner.
3. The method of making a sheet metal article having plane and curved surfaces which consists in forming the areas which are surfaces of revolut'on of a straight line entirely on one piece of plane, sheet metal, forming those areas which are surfaces of revolution of curved lines entirely from other pieces of sheet metal and welding the edges of the several pieces together to form one continuous surface of the desired shape.
4. The method of making a. sheet metal sink which consists in preparing a sheet of metal for constructing the main or central portion of the sink, rolling the longitudinal edges into cylindrical-like shape, bending parallel port'ons of the sheet upwards to form respectively the front and. back of the sink with easilycleanable curves at the bends, preparing two sheets of metal shaped for the two ends of the sink, bending the bottom portion of each end piece in well rounded curves to join the bottom portion of the main sheet and s'milarly bending the front and back portions of the ends to join the front and back sides of the main portion of the sink, bending the tops of the ends into cylindrical-like shape comparable to the rolled longitudinal edges of the main portion, welding the ends onto the man body at the bottom and sides, fitting and welding smoothly rounded pieces of formed sheet metal into the lower and upper corners, removing the rough spots and polishing the ensemble whereby is formed a sheet metal sink with fully rounded curves at top, bottom and corners.
5. The method of making a table top, sink or the like, formed from sheet metal and hav'ng two or more adjacent edges shaped to approximate segments of cylinders, which consists in fitting a segment of a spherical-like shell into the corner space bounded by two of said adjacent edges and welding it into place.
6. The method of making a table top, sink or the like, as specified in claim 5 together with smoothing. off the rough places resulting from the fitting and welding, and thereafter polishing the corner.
RALPH VICTOR HEDLUND.