A rotary knife includes a rotatable annular blade. The blade includes a blade wall presenting an annular inner surface terminating at a cutting edge. The annular inner surface includes a first section and a second section, with the first section extending from the cutting edge and the second section being located further from the cutting edge than the first section. The first and second sections define first and second angles, respectively, relative to an imaginary plane transverse to the axis about which blade rotates. The second angle is greater than the first angle.

A power operated rotary knife including an annular rotary knife blade supported for rotation in a blade housing. The rotary knife blade including a body and a blade section extending from the body. The body includes an outer wall including an arcuate surface having an upper region extending from a first upper end portion to a second intermediate portion and a lower region extending from the second intermediate portion to a third lower end portion. A plurality of gear teeth extend downwardly from the upper end of the body, each of the plurality of gear teeth including an outer peripheral face forming a portion of the upper region of the arcuate surface of the outer wall. The body outer wall includes a bearing surface having a lower bearing face in the lower region of the arcuate surface and an upper bearing face in the upper region of the arcuate surface.

A vacuum rotary knife is fluidly connectable to a vacuum source conduit. The rotary knife includes an annular blade and a knife head. The knife head supports the blade for rotation about a rotational axis. The knife head presents a vacuum port fluidly connectable to the conduit. The vacuum port is spaced from the blade such that the knife head defines a suction pathway extending between the blade and the vacuum port.

A roller cutter for cutting a material includes a rotatable roller, a rotatable blade, and a rotation transmission mechanism. The roller includes an outer rim configured to engage the material at a roller engagement point. The blade includes a cutting edge configured to cut the material at a blade engagement point. The blade engagement point is spaced from the roller engagement point. The rotation transmission mechanism is configured to drivingly interconnect the blade and the roller such that the blade rotates faster than the roller. The roller cutter is configured such that the cutting edge applies both a compressive shear force and a tangential shear force to the material at the blade engagement point as the blade is pressed into the material and the blade and the roller rotate.

A power operated rotary knife assembly including a power operated rotary knife having an annular rotary knife blade, a trim guide, and a drive mechanism for driving the rotary knife blade about an axis of rotation. The assembly also includes a portable power unit, a vacuum assembly and a flexible shaft drive transmission coupled between the power operated rotary knife and the portable power unit. The portable power unit includes a drive motor assembly providing a rotational power source which is operatively coupled to the drive mechanism through the flexible drive transmission to rotate the rotary knife blade. The portable power unit also includes a blower assembly providing vacuum pressure at an inlet duct side, the vacuum assembly being in fluid communication with the inlet duct side to generate a vacuum pressure condition in a region of a cutting opening defined by the rotary knife blade and the trim guide.

An integrated shaving mechanism (ISM) comprises a 28- x 50-mm perforated arbor of 40-mm cylindrical radius supporting a 50-m 300-mg inverted-headfoil-like cutterfoil with a 2540-mm cutting pattern, held slideably under an attached complementary-patterned headfoil. Arbor, cutterfoil, and headfoil provide a few-mm thick shaving mechanism coupled to a shaver body having a motor and eccentric drive shaft that in minor design variations scans the cutterfoil either 1-mm in reciprocation (R-ISM) or 1-mm-R in circulation (C-ISM) at 0.16K-cpm. With its 10-cm.sup.2 area of 0.7-mm-spaced cutting edges capable of firm facial contact, it cuts short hairs at up to 10 the rate of conventional shavers for fast closest-cutting. Arbor-supported cutterfoils and headfoils can be fabricated as thin and lightweight monolayers and multilayers of hard materials and coatings by mechanical and non-mechanical processes. ISMs can be embodied in the size and shape of reciprocator and rotary shavers.

A rotary knife includes a rotatable annular blade. The blade includes a blade wall presenting an annular inner surface terminating at a cutting edge. The annular inner surface includes a first section and a second section, with the first section extending from the cutting edge and the second section being located further from the cutting edge than the first section. The first and second sections define first and second angles, respectively, relative to an imaginary plane transverse to the axis about which blade rotates. The second angle is greater than the first angle.

A vacuum rotary knife is fluidly connectable to a vacuum source conduit. The rotary knife includes an annular blade and a knife head. The knife head supports the blade for rotation about a rotational axis. The knife head presents a vacuum port fluidly connectable to the conduit. The vacuum port is spaced from the blade such that the knife head defines a suction pathway extending between the blade and the vacuum port.

A blade housing assembly for a power operated rotary knife including a split blade housing and a cam mechanism for changing a blade housing diameter between blade supporting and blade changing positions. The split blade housing includes an annular blade support section, a mounting section and a split extending through the mounting section and an inner wall of the blade support section and defining a split distance between first and second circumferential ends of the inner wall. The split includes a radial split section and an angled split section adjacent the inner wall. The mounting section includes first and second body portions on opposite sides of the split. The cam mechanism includes a cam plate bridging the first and second body portions and a cam member rotatably supported by the cam plate. The cam member is rotatable between closed and open positions to change the blade housing diameter.

The disclosed inventive concept provides a rotary cutter and method of accurately cutting a ribbed transmission belt lengthwise to a desired width. The rotary cutter includes an upper portion having a handle end and a pivot end and a lower portion having a handle end and a pivot end. The pivot ends of each portion are joined by a common pivot. A belt input pulley and a rotary cutting wheel are rotatably attached to the upper portion. A drive wheel is rotatably attached to the lower portion. A belt output pulley is rotatably attached to the common pivot. Preferably but not absolutely the belt input pulley and the belt output pulley have ribbed outer surfaces. A cutting wheel cover is fixed around at least a portion of the cutting wheel. The upper portion is movable between an open, belt-fitting position and a closed, belt-cutting position relative to the lower portion.