US2061321A - Chuck construction - Google Patents

Description

Nov. 17,- 1936. H H KNOTT 2,061,321

CHUCK CONSTRUCTION Filed Dec. 4, 1934 v v 1 22321456 5;; 650. i c mc/w Patented Nov. 17, 1936 UNITED STATES CHUCK CONSTRUCTION Harry H. Knott, Washingtomlowa, assignor to American Pearl Button 00., Washington, Iowa,

a corporation of Iowa Application December 4, 1934, Serial No. 755,900

4 Claims.

An object of my invention is to provide a chuck for button blanks or the like, the chuck being comparatively inexpensive to manufacture and simple in its construction.

More particularly it is my object to provide a chuck construction especially adapted for holding button blanks or other semi-fragile elements in such manner that the possibilities of chipping the edges of the blank are minimized and also the tendency for the blank to spring out of the chuck is minimized;

Still another object is to provide a spindlelike chuck element of the split contractible type with a removable element for engaging the button blank or. the like in such manner that it is firmly held without danger of chipping.

Still another object is to provide a split chuck with an annular groove with which a resilient contractible ring may be associated so that the ring itself rather than the metal of the chuck will engage the edge of a button blank or the like to hold itwhil'e performing operations thereon.

A further object is to provide a removable blank engaging element and a method for renewing it, which method is simple and quick to perform.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained', as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawing, in which:

Figure 1 is a plan View of a chuck construction embodying my invention, showing the button blank received therein.

Figure 2 is a. vertical sectional view on the line 2-2 of Figure 1 showing a blank. being held in the chuck and a tool being used on the blank.

Figure 3 is a separated perspective view of my chuck construction comprising a spindle-like chuck element and a renewable resilient blank engaging ring.

Figure 4 is a plan view showing the ring in position and partly split according to my method for renewing the ring.

Figures 5 and 6 are enlarged sectional views on the lines 5-5 and 66 respectively of Figure 1, illustrating the action of the resilient ring of my chuck.

Figure '7 is a plan view of a conventional chuck; and

Figure 8 is a side elevation of another form of chuck including my invention, part of the chuck being broken away.

On the accompanying drawing, I have used the reference character A to indicate generally a spindle-like chuck element and B a resilient ring for association therewith. The chuck A has, as shown in Figure 3, a shank It provided with a cone-portion l2 and an enlarged head it. The head M has therein an annular groove l6 terminating in an outer supporting flange Ill. The chuck is split twice at right angles to each other, they split spaces being indicated at 20. The element A with the exception of the groove l 6 is now in general use and one of such chucks is shown in Figure 7 as A, the parts thereof corresponding to the chuck A, having the same reference numerals with the addition of the distinguishing characteristic a.

The chuck A is shown as having a button blank 0 therein. These blanks are not always perfectly round and the out-of-roundness of the blank C has been exaggerated in Figure '7 so that it contacts at but three points a with the chuck A. Exaggerated spaces 1) are illustrated which in actual practice may be only one or two thousandths of an inch, but nevertheless since the flange l8a is non-resilient and the blank itself is non-resilient, there will be no engagement at these points, so that the blank is engaged at but a very small percentage of its periphery. Accordingly, when a tool, such as a grinder, shown at 22 in Figure 2, is used on the blanks many of them are chipped on the edges and some of them spring out hi the chuck. Chipped blanks, of course, are unusable and there is therefore considerable waste experienced.

By providing the annular groove Hi to receive the resilient ring B as is obvious from an inspection of Figure 3 I am able to overcome the difficulties enumerated in connection with the chuck A in Figure 7. The ring is of slightly greater cross sectional thickness than the width of the groove, as is evident from Figure 5, so that it must be forced into. the annular groove and will accordingly be retained there by its tendency to re-expand to its original thickness. After it is forced into the groove a saw or other cutting tool is run through the split spaces 20, the vertical one of which has been so sawed through as illustrated in Figure 4 and the horizontal one being now ready for sawing through.

The method of installing the ring just described facilitates the installation because it is easier to force the entire ring into the groove than to force individual segments of the ring into the individual segments of the chuck and. get the two in proper relative alignment. The job can be done in less than half the time by this method.

After the ring segments, which are designated by the reference numeral 24, have become too badly worn for further service, they can readily be dug out of the groove segments for the purpose of inserting another ring as just described.

The same out-of-roundness blank C is shown engaged by the chuck A of Figure l as was illustrated in Figure '7. It will be noted that the segments 24 conform to the shape of the periphery of the blank, the sectional Figures 5 and 6 showing respectively relatively loose (yet firm) and tight engagement of the same points on the periphery of less than greater radii respectively. Even where the edges of the blank are relatively loosely engaged as in Figure 5, there would be a slight over-hanging, as indicated at 2B, of the upper edge of the segment 24 with respect to the button blank, this deformation of the segment insuring against the button blank flipping out of the chuck when a tool is used on the blank. The flange segments l8 back up the segments 24 and serve as supports counteracting the tendency for the blank to enlarge the blank-engaging segments 24.

Heretofore. with all metal chucks the flange segments l8 received considerable wear and after ,a few months service the chuck A had to be thrown away, as it would no longer hold the blanks. With my removable insert ring B, however, it is merely necessary to take a few minutes time to renew this element which is very inexpensive and the metal portion of the chuck can thus be used repeatedly for an indefinite length of time. This obviously effects a considerable economy over the old method.

The chuck A is ordinarily used in a drill press type of button blank machine. Some of the conveyor types have chucks such as shown in Figure 8, except that they are all metal and do not include the annular groove I6 and the resilient segments 24, which I have already described. The chuck in Figure 8 is indicated generally by the reference character A" and is of shaft-like construction, similar to the chuck A, but having a taper I2a reversely arranged. On the lower end of the chuck, a thrust ball 28 is provided which travels on a cam track (not shown) which at the proper time raises the chuck, causing the cone lZa to engage a reduced portion of the bore in which the chuck is mounted (not shown) for contracting the chuck. The chuck A is contracted by the cone [2a similarly engaging a part of the machine when the chuck is moved downwardly.

Chucks such as A of Figure 8, when made of all metal, must have their upper ends turned down occasionally as they wear away. The chuck must then be lengthened so as to retain its original length in the machine for proper operation. All of this takes considerable time and skill, whereas with my invention the chuck A" can remain in its original dimensions, the segments 24 being taken out and a new ring B inserted and sawed through, as has been already described, whenever necessary.

From the foregoing description it will be obvious that I have conceived a novel and economical means for removing the blank engaging element on a button blank chuck or the like and that such element is far superior to the all metal chuck now in general use. Although I have described the ring B as being resilient, it is obvious that the degree of resiliency may vary greatly, depending upon the material used to form it. I have found rubber quite satisfactory, although of course, other materials would be suitable. Also, the rubber may be hard or soft as required and a change of this character, as well as others, may be made without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a button blank chuck, a spindle-like chuck element, said element being split into a plurality of parts whereby said parts may be sprung toward each other, an annular groove in an end of said chuck element, a supporting flange outside of and projecting beyond said groove and a resilient button blank engaging ring partially in said groove and partially against said flange, said ring being split coincident with the split spaces of said chuck element.

2. In a button blank chuck, a spindle-like chuck element, said element being split into a plurality of parts whereby said parts may be sprung toward each other, an annular groove in an end of said chuck element, a supporting flange beyond said groove and a resilient button blank engaging ring partially in said groove and partially against said flange.

3. In a chuck construction, a spindle-like chuck element having a depression in one end thereof and an annular groove surrounding said depression, an annular flange surrounding said groove and extending beyond the bottom of said depression and a resilient blank engaging ring partially in said groove and partially against said flange, said chuck element comprising a plurality of parts movable toward each other for contracting said ring.

4. In a chuck construction, a spindle-like chuck element having a depression in one end thereof and an annular groove surrounding said depression, an annular flange surrounding said groove and extending beyond the bottom of said depression and a resilient blank engaging ring partially in said groove and partially against said flange, said chuck element comprising a plurality of parts movable toward each other for contract ing said ring, said ring comprising a plurality of parts one for each part of said chuck element.

HARRY H. KNOTT.

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