US312401A

US312401A - stetson

Info

Publication number: US312401A
Authority: US
Publication date: 1885-02-17
Anticipated expiration: 1902-02-17

Description

(No Model.) 2 SheetsSheet 1. G. R. STBTSON.

MACHINE FOR MAKING TWIST DRILLS.

No. 312,401. Patented Feb. 17, 1 885.

INVENTUR (No Model.) 2.Sheets-Sheet 2.

G. R. STETSON.

MACHINE FOR MAKING TWIST DRILLS.

Patented Feb. 17, 1885.

WITNESEEE INVENTEJR M r fifw y N. PLTERS. PholmLJlhngrnphcr. Washi n nnnnn c UNrrn TATES aren't rrrcn.

GEORGE RIPLEY STETSON, OF NEXV BEDFORD, MASSACHUSETTS, ASSIGNOR TO HIMSELF AND THE MORSE TWIST DRILL AND MACHINE COMPANY,

OF SAME PLACE.

IVlACl-HNE FOR MAKING TWlST-DRILLS.

SPECIFICATION forming part of Letters Patent No. 312,401, dated February 17, 1885.

Application filed October :25, 1883. (No model.)

To (all whom it may concern:

Be it known that I, GEORGE E. SrnrsoN, of New Bedford, in the county of Bristol and State of Massachusetts, have invented certain new and useful Improvementsin Machines for Making Twist-Drills, of which the following is the specification. I

My invention relates to the class of machines illustrated in Letters Patent No. 178, 250,

and to improvements in such machines.

In my improved machine the gradually-expedited advance of the mandrel and blank, in order to obtain the increasing pitch or inclination of the groove, is secured by the action of a suitably-formed cam impinging directly upon the mandrel itself, instead of, as in the patent referred to, upon radial rollerstuds or other equivalent interposed devices between the face of the cam and that part of the mandrel against which its action is brought to bear.

The drawings illustrate a machine of this construction, Figure 1 being an elevation,and Fig. 2 a section, in which a wedge-cam is employed, and Fig.3 being a plan view of the cam and its operating-pinion. Figs. 4 and 5 are views in elevation and section, showing an eccentric in place of the wedge-cam.

The operating mechanism in all the draw ing is substantially like that shown in the granted patent above referred to. The wedgecam may be conveniently constructed in the form of a parallelogram interiorly slotted, and provided upon one exterior side with a 5 rack, a, Fig. 3, by which motion is given to it when such a form of cam is used. I prefer to form the mandrel B at that portion of it exposed to the cam action with an annular boss having a partly-spherical contour,

which bears against the cam.

Instead of the sliding cam, I may use a rotating cam, O, with suitable operating-gearing, 0 c, as shown in Figs. 4 and 5. As the cam is caused, by means of the gears c c or 5 the pinion b and rack a, to act against the mandrel B, the graduated cam-face advances the mandrel which carries the drill D in direct proportion to the pitch of the cam,which,

in turn, is made tocorrespond to the required increased pitch in the drill, and the advance of the madrel being thus increased in speed as the cutting progress, there is a corresponding increase in the pitch of the drill, which increase in pitch it is the object of this machine to obtain.

For the'more convenient return of the man drel at the end of the cutting operation, I pro vide it with an extension, E, bearing against and compressing a spring, 6', as the mandrel advances, which compressed spring, as will be seen, acts to bring the mandrel back after its forward motion has ended.

The other parts of the machine present no substantial difference from those shown in the Letters Patent above referred to. The mandrel is guided in its forward and back motions by its bearings in the gears, which are -splined to it to permit of its passage through them.

From the foregoing it will be perceived that the structure or organization of my improved twist-drill machine is materially simplified; that I dispense not only with the frictionrollers shown in the said patent, but also with the disk provided for carrying the frictionrollers, and transfer the cam action directly to the mandrel,instead of having it communicated indirectly through expensive intermediate appliances. The friction-rollers and the disk in such a machine as the patented one referred to have in practice to be made strong in order to resist the strains applied, and they are consequently expensive. They are also liable to get out of order,and constitute an unnecessary element to the practical efficiency of the machine. Besides this, itis necessary to have more than one bearing upon the cam, where such disk and friction-rollers are employed, as illustrated in said patent, in order to give the proper direction of force of the 0 cam action. This results in the necessity of having what is really a triple cam,equivalent practically to three wedges; otherwise a proper balance of force could not be obtained.

It will be seen that in order to accommodate the change and simplification above set forthI have very greatly modified the construction as well as the relations of the cam applied to the mandrel, and that the result is a materially cheaper, simpler, more efficient, and 5 every way superior machine.

I claim- In a machine for making increased twist-- drills, the combination of a mandrel toadvance and rotate the drill-blank, and a suit- 10 ably-formed cam acting directly against the mandrel, whereby the advance of the latter is accelerated as the cutting progresses to increase the pitch of the drill. 4

In testimony whereof I have hereunto subscribed my name this 18th day of October, A. 15 D. 1883.

GEORGE RIPLEY STETSON. \Vitnesses:

'I. M. STETSON, HENRY B. WORTH.