In a method for producing a cavity (14) in a stator of an eccentric screw pump, material is removed in the interior of a stator blank (10) by means of a tool (11). In order that very long stators can be produced in one production operation, the tool (11) performs a rotational motion through a first shaft (12) and an eccentric motion around a second shaft (13), during which the stator blank (10) and the tool (11) are moved toward each other. A device for performing the method comprises (a) a bearing shaft (3) that can be coupled with its drive end to a first drive and that is rotatable around its longitudinal axis by means of the first drive; (b) a drive shaft (4) that can be coupled with its drive end to a second drive and is arranged in a borehole of the bearing shaft (3) and is rotatable around its longitudinal axis by means of the second drive form-fitting and relative to the bearing shaft (3), and (c) a machining tool (5), which is rotationally fixed connected to the machining end of the drive shaft (4) that can be inserted into the cavity and can be driven rotatably via the drive shaft (4) around the longitudinal axis of the drive shaft (4). The longitudinal axis of the drive shaft (4) intersects the longitudinal axis of the bearing shaft (3) at a point or is arranged askew to the longitudinal axis of the bearing shaft (3).

In a method for producing a cavity (14) in a stator of an eccentric screw pump, material is removed in the interior of a stator blank (10) by means of a tool (11). In order that very long stators can be produced in one production operation, the tool (11) performs a rotational motion through a first shaft (12) and an eccentric motion around a second shaft (13), during which the stator blank (10) and the tool (11) are moved toward each other. A device for performing the method comprises (a) a bearing shaft (3) that can be coupled with its drive end to a first drive and that is rotatable around its longitudinal axis by means of the first drive; (b) a drive shaft (4) that can be coupled with its drive end to a second drive and is arranged in a borehole of the bearing shaft (3) and is rotatable around its longitudinal axis by means of the second drive form-fitting and relative to the bearing shaft (3), and (c) a machining tool (5), which is rotationally fixed connected to the machining end of the drive shaft (4) that can be inserted into the cavity and can be driven rotatably via the drive shaft (4) around the longitudinal axis of the drive shaft (4). The longitudinal axis of the drive shaft (4) intersects the longitudinal axis of the bearing shaft (3) at a point or is arranged askew to the longitudinal axis of the bearing shaft (3).

A bit for drilling with a casing or liner string includes: a tubular stem made from a high strength metal or alloy; a head: having a cutting face with an inner cone, an outer shoulder, and an intermediate nose between the cone and the shoulder; attached to an end of the stem; and made from a nonferrous metal or alloy; a plurality of blades formed integrally with the head, made from the nonferrous metal or alloy, and each extending from a center of the cutting face to the shoulder; a plurality of superhard cutters mounted along each blade; a plurality of gauge pads formed integrally with the stem; and a flush joint formed between each blade and a respective gauge pad. A yield strength of the high strength metal or alloy is at least twice a yield strength of the nonferrous metal or alloy.

A bit for drilling with a casing or liner string includes: a tubular stem made from a high strength metal or alloy; a head: having a cutting face with an inner cone, an outer shoulder, and an intermediate nose between the cone and the shoulder; attached to an end of the stem; and made from a nonferrous metal or alloy; a plurality of blades formed integrally with the head, made from the nonferrous metal or alloy, and each extending from a center of the cutting face to the shoulder; a plurality of superhard cutters mounted along each blade; a plurality of gauge pads formed integrally with the stem; and a flush joint formed between each blade and a respective gauge pad. A yield strength of the high strength metal or alloy is at least twice a yield strength of the nonferrous metal or alloy.

Processing is performed from the front end of a bulb to a connection portion with a shaft along an inclined surface of the bulb, using a rotary tool that is inclined at an angle formed by a connection point of a radius of the shaft with a radius of the bulb and the front end of the bulb; then, processing of the shaft is performed, and a stylus is manufactured.

Processing is performed from the front end of a bulb to a connection portion with a shaft along an inclined surface of the bulb, using a rotary tool that is inclined at an angle formed by a connection point of a radius of the shaft with a radius of the bulb and the front end of the bulb; then, processing of the shaft is performed, and a stylus is manufactured.

An object of the present invention is to provide a power steering apparatus and a method of manufacturing a power steering apparatus that allow balls to smoothly travel in a connection member for circulating the balls. To achieve this object, a first curved portion of a first connection passage of a nut that faces a first bent portion of the connection member is formed into a curved shape in such a manner that a space between the first curved portion and the first bent portion is equal to or smaller than a predetermined value. Further, a second curved portion of a second connection passage of the nut that faces a second bent portion of the connection member is formed into a curved shape in such a manner that a space between the second curved portion and the second bent portion is equal to or smaller than a predetermined value.

An object of the present invention is to provide a power steering apparatus and a method of manufacturing a power steering apparatus that allow balls to smoothly travel in a connection member for circulating the balls. To achieve this object, a first curved portion of a first connection passage of a nut that faces a first bent portion of the connection member is formed into a curved shape in such a manner that a space between the first curved portion and the first bent portion is equal to or smaller than a predetermined value. Further, a second curved portion of a second connection passage of the nut that faces a second bent portion of the connection member is formed into a curved shape in such a manner that a space between the second curved portion and the second bent portion is equal to or smaller than a predetermined value.

A constant rake planar cutting edge fluted drill bit and a method of manufacturing the same. The drill bit includes a planar cutting face formed at the tip end of the bit by a motion of a rotating machining wheel respective to a stationary blank in a first step. Once the cutting face is formed, the blank is rotated and translated in a direction parallel to an elongated axis, during which the rotating machining wheel creates a flute. Upon completion of the first flute, the bit is rotated accordingly and the processes are repeated to create each subsequent planar cutting face and respective flute. The process can also be completed in a slightly modified version of a reverse process, fabricating a flute prior to formation of the planar cutting face of the bit.

A constant rake planar cutting edge fluted drill bit and a method of manufacturing the same. The drill bit includes a planar cutting face formed at the tip end of the bit by a motion of a rotating machining wheel respective to a stationary blank in a first step. Once the cutting face is formed, the blank is rotated and translated in a direction parallel to an elongated axis, during which the rotating machining wheel creates a flute. Upon completion of the first flute, the bit is rotated accordingly and the processes are repeated to create each subsequent planar cutting face and respective flute. The process can also be completed in a slightly modified version of a reverse process, fabricating a flute prior to formation of the planar cutting face of the bit.