US469813A - Carl georg dahlgren and john hugo svensson - Google Patents

Description

UNITED 'STATES PATENT OFFICE.

GTEBORG,

LATH E.

SPEGIFIGATION forming part of Letters Patent No. 469,813, dated March -1, 1892.

Application filed J'anuary 19, 1891. Serial N0. 378,300. (N0 model.)

T0 all whom it may corwern:

Be it known 1 ;hat we, CARL GEORG DAHL GREN and JOHN HUGO SVENSSON, both subjeets of the King of Sweden, residing at Gteborg, in the Kingdoxn of Sweden, have inventedacertain new and useful Improvegnent in Lathes,of which the followlng is a speeifica-tion.

The objeet of this invention is. to enable prismaticor angular se ctions to be turned in a lathe bymeans of simple meehanisrn.

Aeeording 120 this inven tion both the pieees 0f wood, metal, marble, stone, 01 ahy other material required t0 be turned, as he-reinafter deseribed, and f0r which Ehe latl1e is made of suitable strength, respe'ctivelf7, (these pieees being hereinafter ealled the blank,) and also the eutting-tool are rotated simultaneous1y with different ratlos 0f veloeity, aeeording to the shape of section to be given to the piece when turned. By tl1is means sections having regular forms may be turned, said forms having (when the radius 0f the cuttingtool is equal to the great-est radius 0f the 0bject turne'd) a number of angles dependent on the velocities aeeording to the formula 12 91:0 where n equals the number 0f angles, c the nurnber 0f blades on phe oireumference of the cutting-tool, 'v he rotary veloeioy of he tool, and v the rotary veloeity of the blank. Thus a cutter having two eqnidistant blades will, if driven with a veloeity double that 0f the blank, Gut out a four-angled .figu're of seetion,1ahe faees 0f which are slightly convex. If driven with a veloeity treble that 0f the blank, lt Will cut out a hexagonal figure the faces of which will be slightly eoneave.

In the aecompanying drawings, Fignre 1 is a plan view of a lathe fitted with the improvements. Fig. 2 is a diagram matic section show- Ing the turning of a four-angled figure. Fig. 3 is a similar view showing the turning of a hexagonal section.

In the drawings, A is the blank, which is fixed-on the live-spinclle e in the usual manne1. The live-spindle e drives the shaft 2 by means of toothed wheels 2 e On the shaft 2 is the toothed wheel 2 whieh gea1s with the spherieal toothed wheel z, through whieh passes the shaft d, conneeted '00 rotate with be wheel z by means of a long feather d thereon moving in a keyway in the wheel, so

with usual adjustments parallel to and. perpendieular to bhe blank. The joint eonneeting the shafos d and a may be of any known construetion 0f rocking joint, whereby the shaft d may revolve the shaft a at all times, whatever may be the relative an gular position of the axes 0f the shafts during the working 0f the xnachine. By replaeing t he one or other pair of wheels z 2 0r 2 2 by similar gearingwheels of different relative sizes the proportion between the veloeities of the spindle e and shaft d therefore between the blank and the cutting-tool may be altered at will.

In cutting out a four-angled seetion the blade 0f the tool B meecs the surfaee of the blank a1: the point y and, moving in the direetion of the arrow, will have reached Ehe point y, traveling through the angle x, while the blank has moved through the angle i%besubtends an angle of sixty degrees, er twothirds of a right angle. The veloeities being as two t0 0n e the other eutting-blade b 0f he tool will reach the point y exactly as the point z (where the former cut ended) arrives at said point y. The cut; 2 y will then be made by tl1e blade b Similarly ehe cut y y is made by the blade b, and the cut y y by the blade b, thus completing the figure.

The numerals I t0 VII and l to 7 illustrate relative simultaneous positions.

T0 cut a hexagonal figure, the veloeity 0f the tool is t that of the blank as tl1ree to one.

Tl1e 13001 therefore passes throngh the angle w,

while tlie blank revolves through the angle% The am u will snbtend the sum of these angles, and (the figxe being six-sided) this snm will therefore be sixty degrees, and the angle v will thus be forty-five degrees. The tool rotates throngh a distance of half its circunnference while the blank moves through a sixth only. Therefore the blade b will meet the point u at the position t and will cnt thepart u u. Similarly the blade b will cnt u u and again u u, and the blade 12 will eut u u and u t. Similarly by use of diiferent proportions of velocities and equivalent adjustment of the angle subtendin g 'the overlapping part of the two circles other figures may be cut out.

It Will be understood that by approaehing the t-0ol to the blank so that the angle aforesaid is greater than its true Proportion the figure will simply be ent to a smaller scale, while by setting ehe tool at a greater distance fron1 the blank the part necessary to complete a face ot the figure will not be all rernoved, but a less portion will be rennoved, the eifeet being to leavea portion of the original circalar cirenmference between eaeh cut.

- We claim as our invention- In a lathe, the eombination ot' tl1e live-spin- .dle e, adapted t0 receive and revolve a blank,

CARL GEORG DAIILGREN. JOHN HUGO SVENSSON.

Witnesses:

CHARLES I-l. SHEPARD, HUGO ARWIDSSON.

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