US 3343573 A
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Description (OCR text may contain errors)
Sept. 26, 1967 J. J. DILLON ROVING CAN SPRING Filed April 14, 1 965 FIG. 2
S m W N A R E 0 W3 3 U A 4 Nfi w G JY II B F m 5 v G M l 7 F 7 c United States Patent 3,343,573 Patented Sept. 26, 1967 ABSTRACT OF THE DISCLOSURE Method of providing a roving can spring by winding wire about a mandrel to form a number of coils, pulling out the coils to a predetermined distance, and during this step of pulling out the coils, turning the coils a predetermined number of revolutions, then heat treating the pulled-out coils and cooling the heated coils at room temperature.
Heretofore, in the manufacture of roving can springs, it has been usual to form the same out of wire at room temperature and Without any heat treatment. It has been found that, where high carbon hard drawn medium bright wire was used, the spring would lose some of its elasticity after short usage. It was also found that a much more eX- pensive tempered wire was required in order to prevent a sagging or loss of lifting power after short usage. In both cases, however, the wire was wound without an after-heat treatment.
This invention relates to the use of the low-cost, high 39 carbon hard drawn medium bright Wire forming the same into the spring of the desired size and then relieving the stresses in the wire by heat treating so that the spring will acquire a property by which it will stand up for long pe- 4O riods of use without sagging and losing height.
One of the objects of the invention is, therefore, to provide by a treatment of the spring after formed to size, so as to prevent the spring from losing its lifting power.
Another object of the invention is to provide a roving can spring out of minimum expense wire and yet attain the properties of the more expensive tempered Wire with an overall saving in cost.
predetermined length and pulled out to a predetermined length;
FIG. 4 is a perspective view showing a plurality of springs in a container about to enter a heating chamber for treating the same; and
FIG. 5 is a view showing the spring as pressed together and bound for shipment.
In proceeding with this invention, I wind the wire in closely adjacent coils about a mandrel and then sever the same at predetermined points and then axially stretch the wire out to a predetermined length. Then a number of the coils or springs so formed are stressed relieved by placing the same in a heating chamber for a certain length of time and then allowing the same to cool in the atmosphere to atmospheric temperature. After this the coils are compressed and bound for shipment.
With reference to the drawings, 10 designates a cylindrical mandrel and about this there is wound coils of wire 11 in a snug relationship so that one coil substantially abuts another, this Wire being continued for a substantial length. After the wire is so wound, it is taken from the mandrel and cut every so often to provide a certain number of coils, depending upon the height of the can which 5 it is to be fitted for. The closely wound coils are then stretched axially such as shown in PEG. 3 at 12 to a predetermined axial length when released which will be substantially the height that the spring is intended to assume and at the same time a fraction of a turn or more than one turn may be taken out of the coil.
A plurality of these springs so formed are then placed in some sort of a carrier 13 which may hold a substantial number of springs, and the same is placed in a furnace 14, such as through doors 15, and left at a temperature of 400 F. in this furnace for a period of thirty minutes after which the carrier is removed from the furnace and the springs are allowed to cool in the atmosphere to atmospheric temperature, which provides a stress relieving operation.
After the stress relieving operation, the springs may be compressed and tied as at 16 by ties 17 afiording them a package which may be shipped.
The lifting capacity of the springs after stress relieving or heat treating in this manner has shown that they increase their lifting power materially. Comparisons of pounds lifting power before and after heating in this mannet are provided in the following table:
Size No. of Adjusted Coil Lift Be- Lift After Percent Coils Height Dia. fore Heat Heat Increase I claim:
With these and other objects in view, the invention consists of certain steps taken in the method of manufacturing the roving can spring and with reference to the drawings:
FIG. 1 is a perspective view partly broken away showing a roving can with the spring therein;
FIG. 2 is an elevation showing a mandrel with the wire of the spring tightly wound thereon as a first step in the production of the spring;
FIG. 3 is an elevational view of the spring cut to a 1. The method of making a roving can spring which comprises the steps of winding high carbon hard drawn medium bright wire about a mandrel to form a predetermined number of coils, pulling out the coils to a predetermined distance, and during this step of pulling out the coils, turning the coils a predetermined number of revolutions, then heat treating the pulled-out coils to relieve the stresses therein, and cooling the heated coils at room temperature.
'3 a 4 2. The method of claim 1 wherein the heat treating 1,865,490 7/ 1932 Wadsten et aI 723 64 is at about 400 F. for about thirty minutes. 2,745,658 5/ 1956 Gaskins 14812 3,002,865 10/1961 Johnson 29173 References Cited W. Primary Examiner.
716,680 12/1902 Daniels et a1 "140-89 LARSON, Assistant Examiner-