US 4,112,794 AGranted

Tube cutter with phase changer

AssigneeBurr Oak Tool & Gauge Company

InventorsLawrence A. Franks, Steven L. Stroup, James E. Perry

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Abstract

A tube cutoff device which includes a rotatable cutter head for radially slidably supporting a cutter and a pair of support rollers in circumferentially spaced relationship. A stationary tubular guide extends through the cutter head for permitting a tube to be fed therethrough and positioned between the cutter and the support rollers. A cam is rotatably supported on the cutter head and cooperates with the cutter and rollers for displacing same radially inwardly into engagement with the tube which is to be cut. The cutter head and the cam are rotatably drivably connected to first and second power trains, respectively, which cause the cam and cutter head to normally rotate at the same rotational speed. A phase change device is coupled between the first and second power trains and, when activated, causes the second power train and hence the cam to be rotated at a slightly different rotational speed, which differential rotational speed causes the cutter and support rollers to be cammed radially inwardly for supporting and cutting engagement with the tube.

Claims11

Dependent claims

In an apparatus for cutting a tubular element, said apparatus having a frame, means associated with said frame for holding an elongated tubular element, and a rotatable cutting head assembly positioned in surrounding relationship to said tubular element and rotatable about an axis substantially aligned with the axis of said tubular element, said cutting head assembly including rotatable support means having a rotatable cutting element mounted thereon for rotation therewith, and mounting means coacting between said cutting element and said support means for permitting said cutting element to move radially inwardly into rolling engagement with the tubular element to effect cutting thereof as the cutting element rolls therearound due to rotation of said support means, the improvement comprising ringlike cam means concentrically rotatably supported on said support means, said cam means having a cam surface cooperating with said mounting means for causing the cutting element to be urged radially inwardly toward the tubular element so as to rollingly cuttingly engage same, and drive means for causing high speed rotation of said support means and said cam means, said drive means including first and second power transmission means respectively drivingly connected to said support means and said cam means for normally causing rotation thereof at the same rotational speed, said drive means also including phase change means coacting with at least one of said power transmission means for selectively causing a small rotational speed differential between said support means and said cam means, said speed differential causing said cam means to relatively rotate with respect to said mounting means for camming said cutting element radially inwardly for engagement with the tubular element.

In a tube cutting apparatus, the combination comprising:

frame means, including tubular guide means defining an axis along which an elongated tubular workpiece is fed;
sleevelike head means rotatably supported on said frame means for rotation about said axis;
annular cam means rotatably supported for rotation about said axis, said cam means being disposed adjacent and coaxially aligned with said head means;
at least three workpiece engaging assemblies radially movably supported on said head means in angularly spaced relationship, each said assembly including a cam follower disposed in engagement with said cam means and a rollerlike engaging element adapted to be moved into engagement with said workpiece, at least one of said engaging elements comprising a cutting roller;
first rotatable motor means;
first power transmission means drivingly connected between said first motor means and one of said head and cam means for rotating same at a first rotational speed;
second power transmission means drivingly connected between said first motor means and the other of said head and cam means for normally rotating same at a second rotational speed which is equal to said first rotational speed;
drive means interconnected to said second power transmission means for causing variation in said second rotational speed so that it varies slightly from said first rotational speed to thereby cause said cam means to be angularly displaced about said axis relative to said head means;
said drive means including second motor means, and third power transmission means drivingly connected between said second motor means and said second power transmission means for permitting variation in said second rotational speed;
whereby the variation in said second rotational speed causes said anular displacement between said cam means and said head means so that said workpiece engaging assemblies are cammed radially inwardly toward the workpiece so that said cutting roller rollingly engages and cuts the workpiece as it rotates therearound.

7 more elements

Dependencies are inferred from the claim text.