Patent Application
20080196472
This invention relates generally to metal forming and more particularly to preparing tubing for manufacture of outer races for tapered roller bearings.
Various ways are known to make outer bearing races (usually referred to as “cups”) for tapered roller bearings. Typically they involve using a seamless tube made of steel and cross-cutting it into rings followed by machining the rings to form a smooth cylindrical outside diameter (O.D.) and a conical I.D. One of the known ways to cut the tube into rings is to use a gang saw as disclosed in U.S. Pat. No. 5,293,794 issued to Mosey et al. on Mar. 15, 1994. That saw provides an advantage over prior saws in that the amount of tube material lost due to the kurf of sawblades with prior equipment was reduced, so that more rings can be produced from a length of tubing. There remains an interest in optimizing the production of useful parts from a length of tubing.
According to one feature of my invention, instead of a smooth cylindrical inside wall of the tube, it is treated to reduce the amount of material removal which would otherwise occur in the machining of the bearing cups produced from the tube. Another feature is forming the interior surface of the tube into a shape similar to the desired shape for the bearing cup I.D.
Another feature is roll forming of the shape.
In one embodiment of the present invention, instead of a smooth cylindrical inside wall of the tube, it is treated to reduce the amount of material removal which would otherwise occur in the machining of the bearing cups produced from the tube.
Another feature of the present invention is forming the interior surface of the tube into a shape similar to the desired shape for the bearing cup I.D.
Another feature of the present invention is roll forming of the shape.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings, and specific language will be used to describe that embodiment. It will nevertheless be understood that no limitation of the scope of the invention is intended. Alterations and modifications in the illustrated device, and further applications of the principles of the invention as illustrated therein, as would normally occur to one skilled in the art to which the invention relates are contemplated, are desired to be protected. In particular, although the invention is discussed in terms of a blood glucose meter, it is contemplated that the invention can be used with devices for measuring other analytes and other sample types. Such alternative embodiments require certain adaptations to the embodiments discussed herein that would be obvious to those skilled in the art.
Referring now to the attached drawing, a pair of rolls 11 and 12 in a tube rolling mill are shown having received a pierced seamless tube shell 13 between them. An arbor 14 is provided inside the tube. The rolls themselves are conical from their ends toward a circular crown area such as 16, and are skewed as show at 11A in
Briefly stated, the shaped arbor 14 is introduced into the trailing end of a pierced seamless tube shell heated to 2,250 degrees Fahrenheit. The arbor length will be the length of the tube plus approximately 20% projecting out the tail end of the tube because, as the tube is processed through the rolls, it will become elongated. In an elongating mill or like mill and setting the roll gap smaller than the shell outside diameter (O.D.), the shell is forced down onto the shaped arbor. The arbor is circular about a longitudinal axis 18 which is also the axis of the tube 13. As the rolls turn and being skewed as they are, advance the tube shell, the shell will go into the rolls round and be squeezed oval as the rolls rotate it and move it against the arbor at the gap, rotating the arbor along with the tubing. As the tubing exits the roll gap, it expands radially to its original O.D. or slightly less. This results in an air gap 19 created between the outer surface of the arbor and the inner surface of the shell as the shell exits the rolls. After the entire tube has passed through the rolls, the arbor can be removed by simply pulling it out of the tube.
The completed tube can then be cross-cut at 21, 22 and 23, for example, to make two O-rings having conical inside faces which can then be lightly machined and ground or otherwise treated for finishing into a bearing cup. Thus it is seen that the arbor is shaped for a succession of generally conical faces in alternate directions of taper relative to the axis 18 to provide a series of alternating conical inside faces of the tube shell which can then be converted readily to bearing cup rings.
U.S. Pat. No. 5,406,820 issued to me on Apr. 18, 1995 discloses an organization of gripping rolls and material feed into such rolls. Other arrangements may also be used.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the description is to be considered as illustrative and not restrictive in character. Only the preferred embodiment, and certain other embodiments deemed helpful in further explaining how to make or use the preferred embodiment, have been shown. All changes and modifications that come within the spirit of the invention are desired to be protected.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/715,340 filed Sep. 8, 2005.
| Number | Date | Country | |
|---|---|---|---|
| 60715340 | Sep 2005 | US |
