US923732A - Method and means for working eccentrically-rotating parts. - Google Patents

Description

APPLICATION FILED 13110.21, 190 7.

Patented June 1, 1909.

/v vE/Yf WI Tit 5856 that the shaft has inconveniences and difficulties.

" mechanical engineer,

.being especially UNITED STATES OFFICE,

. I I 0F.' SWEDEN.

' lo.all whom it may concern:

Be it known that I, ERNST THUNBI-me,

subject of Sweden, residing at Bofors, in the county of Wermland,

Sweden, have invented new and useful Improvements in Means for Working Eccentricall'y-Rotating Parts, of which the following is a s ecification.

In wor g, for instance turning,.grinding and polishing eccentrically rotating parts such as the cranks on crank shafts the method hitherto employed has been either, been mounted in-a fixed position and the tool been rotated around the crank, or in most cases that on the endscf the shaft have been fixed pieces, that have been mounted between the centers of a lathe so that the axis ofthe crank has coincided with the axis of said centers whereupon the crank has been turned or ground in the usual manner. This, however, has caused several The whole shaft with exception only of the crank being worked will rotate eccentrically with relation to the axis of the centers and thus cause an unevem motion and an extremely inconvenient strain on the machine, this strain important in.working large and consequently heavy pieces. The eccentrically rotating masses also will make the Working with a great speed diflicult, what otherwise would be possible with rapidly cutting steel. A third inconvenience is, that if several cranks are situated on the same shaft only one ca-n be worked at a time. It

has also been proposed to ,mount the shaft being not quite'independent and positive but m some way controlled by the pin itself. This method, however, is unpractical, because only the shape of the pin, but not the crank radius thus will be exactly determined by the tool. 1

According to the present invention, the shaft is mounted in-the last mentioned way,

Specification of Letters Patent.

Application med December 21, Serial No. 407,660.

Fig. 2 in a reduced scale the Patented June 1 1909.

that is, ooaxiall -with the centers, and is worked by a too that is moved in a'vertical and horizontal direction together with the crank-pm, but such motion 0 the tool in this case 1s fully and sitively determined by a, special gear so t at the tool can work the rotating part (e. g. the pin) in a manner that is not dependent uponthe motion of the pm.

The method is illustrated in the accompanyi-ng drawin where it is shown as employed on a sha with two cranks.

Figure 1 illustrates the device for causing t e motion of the tool in elevation and shaft in position together with two working tools.

1 is the, shaft, 2 the cranks, 3 the centers of the lathe and 4 the tool-holders, each of which is mounted in the example illustrated in the same way as a connecting-rod on two 4 plates 5, such plates having a rotating motion so adapted, that the tool 6 will describe a circle around the crank-pin during the rotation of the latter. The plates'are provided withholes 7 or other securing devices on different distances from the center, so that the. motion of the connecting-rods can be varied according to the radius of the crank to be worked. The plates 5 are driven by a suitable gearing from the same source of pfower as the lathe or grinding machine itsel 'Having now particularly described and ascertained the nature of-my invention and in what manner the same is performed, I declare that what I claim is:

1. In a device for turning the crank pins of crank shafts and the like, means for supporting the crankshaft, a pair of rotatable elements, arranged in line with each other and said crank pin, a bar, journals connecting the bar with said rotatable elements, a

tool carried by the end of the bar in contact with the crank pin to be turned, and means for rotating the crank shaft and said elements synchronously.

2. In a device for turning the crank pins of crank shafts and the like, means for supporting thecrank shaft,.a pair of rotatable disks arranged in line with each other and said crank pin, a bar, a pair of pivots car ried by said bs-r, said hairin holes I In testimony whereof I have signed my therein with which the pivots of the argue name to this specification in the presence of adalifed to engage whereby the position "of twi) subscribing witnesses.

the 7 :11- may be adjusted, a tool carried b ERNST THUN BERG.

5 the end of the bar] in contact with the cran Witnesses: I v pin, and means for rotatin the crank shaft JOHN EDBERG,

and said disks synchrono y. H. TmZANnER.

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