Patent Description:
Cutting tools having a cutting insert releasably retained in an insert pocket of a tool body can be provided with a cooling mechanism. The cooling mechanism can be provided by one or more coolant ducts, having coolant outlets, for conveying coolant fluid to a cutting portion of cutting insert. An example of such a cutting tool is disclosed in, for example, <CIT>, where the coolant outlet is located rotationally forward of the cutting insert. Another example is <CIT>, which discloses a tool body according to the preamble of claim <NUM>, where the coolant outlet is formed with a separate distributing element. The tool bodies of such cutting tools are made from steel and are manufactured by traditional methods such as, for example, turning, milling and drilling. The coolant ducts are created during a post manufacturing process by drilling a hole from the outside of the tool body.

Alternatively the tool body can be manufactured by newer techniques, such as Additive Manufacturing. Additive Manufacturing refers to a class of manufacturing processes, in which a part is built by adding layers of material upon one another. This allows, in the case of tool bodies, the coolant ducts to be created at the same time the tool body is manufactured. This permits the coolant ducts to have an unusual structure (e.g. a non-circular cross-section) that is not limited as in the older techniques mentioned above. It also allows the coolant ducts to be curved. An example of such a cutting tool is disclosed in, for example, <CIT>.

It is an object of the subject matter of the present application to provide a new and improved cutting tool and tool body.

It is a further object of the subject matter of the present application to provide a cutting tool and tool body with an improved cooling mechanism.

In accordance with a first aspect of the subject matter of the present application there is provided a cutting tool having the features of claim <NUM>.

In accordance with a second aspect of the subject matter of the present application, there is also provided a tool body having the features of claim <NUM>.

It is understood that the above-said is a summary, and that features described hereinafter may be applicable in any combination to the subject matter of the present application, for example, any of the following features may be applicable to the cutting tool:
The coolant deflection portion can completely overhang the outlet orifice.

The coolant chamber can be recessed in the tool body surface so that the coolant deflection portion does not protrude from the tool body surface.

The outlet orifice can be generally circular.

The chamber deflection surface and the chamber orifice surface can be planar. The two chamber minor surfaces can be are concavely curved.

The outlet orifice can define an outlet orifice plane. The outlet orifice can have an outlet orifice axis which is perpendicular to the outlet orifice plane. The chamber deflection surface can form a chamber deflection angle with the outlet orifice axis. The chamber deflection angle can be in the range <NUM>° < β < <NUM>°.

The chamber orifice surface can be parallel to the outlet orifice plane.

The coolant chamber can extend along a chamber central axis that passes between the chamber deflection surface, the chamber orifice surface and the chamber minor surfaces. As measured in a cross-sectional plane perpendicular to the chamber central axis, the coolant chamber can have an increasing cross-section, in a direction towards the coolant chamber opening.

The coolant chamber can extend along a chamber central axis. In a cross sectional plane perpendicular to the chamber central axis, the chamber deflection surface and the chamber orifice surface can be longer than the two chamber minor surfaces.

The cutting insert can comprise a cutting edge. The coolant chamber opening has an elongated shape that can extend longitudinally generally in the same direction as the cutting edge.

The length of coolant chamber opening can be at least <NUM>% the length of the cutting edge.

The tool body can comprise exactly two coolant ducts.

The insert pocket can comprise a pocket base surface and a threaded bore opening out thereto. The two coolant ducts can extend on either side of the threaded bore.

The cutting tool can be configured to rotate in a direction of rotation around the central tool axis. The tool body can comprise a forward facing body face surface and a body periphery surface, the body periphery surface extending circumferentially along the central tool axis and forming a boundary of the body face surface at a forward end of the cutting tool. The coolant chamber opening can be located rotationally behind the insert pocket.

The coolant chamber opening and the insert pocket can be aligned in the circumferential direction of the cutting tool.

The cutting tool can be configured to rotate in a direction of rotation around the central tool axis. The tool body can comprise a forward facing body face surface and a body periphery surface, the body periphery surface extending circumferentially along the central tool axis and forming a boundary of the body face surface at a forward end of the cutting tool. The insert pocket can open out to the body face surface. The coolant chamber opening can be angularly aligned with the insert pocket about the central tool axis.

The cutting tool can be a rotary milling cutter.

The tool body can comprise a forward facing body face surface and a body periphery surface, the body periphery surface extending circumferentially along the central tool axis and forming a boundary of the body face surface at a forward end of the cutting tool. The insert pocket can open out to the body face surface. The coolant chamber opening can be located underneath the insert pocket. The cutting tool can be a turning tool not configured to rotate around the central tool axis.

The cutting insert can have a cutting edge which extends along the tool central axis in the forward-to-rearward direction. The coolant chamber opening can extend longitudinally generally in the same direction as the cutting edge. The coolant chamber opening can be positioned, relative to the insert pocket, so as to direct a coolant over and along a relief surface associated with the cutting edge such that the coolant impacts a juncture between the cutting edge and a workpiece being cut by the cutting tool.

For a better understanding of the present application and to show how the same may be carried out in practice, reference will now be made to the accompanying drawings, in which:.

For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity, or several physical components may be included in one functional block or element. Where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

In the following description, various aspects of the subject matter of the present application will be described. For purposes of explanation, specific configurations and details are set forth in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will also be apparent to one skilled in the art that the subject matter of the present application can be practiced without the specific configurations and details presented herein.

Attention is first drawn to <FIG> showing a cutting tool <NUM>, for chip removal, in accordance with embodiments of the subject matter of the present application. The cutting tool <NUM> has a cutting insert <NUM> which can be typically made from cemented carbide. The cutting tool <NUM> also has a tool body <NUM> which can be typically made from steel and is manufactured by an Additive Manufacturing process. In this non-limiting example shown in the drawings, the Additive Manufacturing process used is Direct Metal Laser Sintering. However, other Additive Manufacturing techniques can be used.

In this non-limiting example shown in the drawings, the cutting tool <NUM> is a rotary milling cutter. It is noted, however, that the subject matter of the present application also applies to other types of cutting tools, for example, but not limited to, turning tools. The cutting tool <NUM> is adjustable between a released and fastened position. In the fastened position of the cutting tool <NUM>, the cutting insert <NUM> is releasably attached to the tool body <NUM>.

The tool body <NUM> includes a tool body surface <NUM>. The tool body <NUM> includes an insert pocket <NUM>, for retaining (i.e. seating) a cutting insert <NUM> therein. The insert pocket <NUM> is recessed in the tool body surface <NUM>. It is understood that the term "recessed" when used in respect to an element related to the tool body <NUM> refers to a structure that is created during the additive manufacturing of the tool body <NUM>, and not in a post manufacturing machining process. In accordance with some embodiments of the subject matter of the present application, the insert pocket <NUM> can include a pocket base surface <NUM> and a pocket side surface <NUM> oriented transversely thereto. The insert pocket <NUM> can include a threaded bore <NUM> that opens out to the pocket base surface <NUM>. The threaded bore <NUM> is for threadingly engaging a retaining screw <NUM> as described in the description hereinafter.

The cutting insert <NUM> has a cutting edge <NUM> formed at the intersection of a rake surface <NUM> and a relief surface <NUM>. Reference is now made to <FIG>, showing a detail of <FIG>, where the cutting insert <NUM> is releasably retained in an insert pocket <NUM> of the tool body <NUM>. In this non-limiting example shown in the drawings, the retaining screw <NUM> is used to clamp the cutting insert <NUM> in the insert pocket <NUM> of the tool body <NUM> through a through bore. However, other clamping methods may be used. It is noted that the cutting insert <NUM> and the seating thereof in the insert pocket <NUM> is known in the field of metal cutting and is not part of the invention.

Referring now to <FIG>, the tool body <NUM> includes a coolant chamber <NUM> that opens out to the tool body surface <NUM> at a coolant chamber opening <NUM>. The coolant chamber <NUM> can be closed at the end opposite the coolant chamber opening <NUM> by a chamber end surface <NUM>. The coolant chamber is designed to direct coolant fluid towards the cutting edge <NUM> of the cutting insert <NUM> with which it is associated. The coolant fluid can be, for example a liquid, such as oilbased or chemical coolants or a gas, such as air. The coolant chamber <NUM> can extend along a chamber central axis C. The chamber central axis C can pass between the chamber deflection surface <NUM>, the chamber orifice surface <NUM> and the chamber minor surfaces <NUM>. The chamber central axis C can pass through the coolant chamber opening <NUM> and intersect the chamber end surface <NUM>. In accordance with some embodiments of the subject matter of the present application, the coolant chamber opening <NUM> can have an edge that extends smoothly, i.e. with no jagged portions, around its periphery.

As seen in <FIG>, in a front view of the coolant chamber <NUM> (defined later in the description) the coolant chamber opening <NUM> can have a generally rectangular shape. The coolant chamber opening <NUM> is spaced apart from the insert pocket <NUM> by an opening distance D. The value of the opening distance D can vary along the length coolant chamber opening <NUM>. The optimal value of the opening distance D is determined by several factors. One such factor is the desire for the coolant fluid to avoid the base of the cutting insert <NUM> (which may protrude from the insert pocket <NUM>) when it exits from the coolant chamber opening <NUM>. The opening distance D is ideally less than <NUM>.

As seen in <FIG> and <FIG>, the coolant chamber opening <NUM> has an elongated shape. The coolant chamber opening <NUM> can extend longitudinally generally in the same direction as the cutting edge <NUM>. In this non-limiting example shown in the drawings, e.g. <FIG>, the coolant chamber opening <NUM> is oriented approximately at a <NUM>° angle with respect to the cutting edge <NUM>, so that the opening distance D decreases uniformly. The length of coolant chamber opening <NUM> can be at least <NUM>% the length of the cutting edge <NUM>. Advantageously, this allows at least a majority of the length of the cutting edge <NUM> to receive coolant fluid. Due to its elongated, non-circular shape, the coolant chamber opening <NUM> is configured to supply a stream of coolant having a non-circular cross-section.

In accordance with some embodiments of the subject matter of the present application, the coolant chamber <NUM> can be formed peripherally by a chamber deflection surface <NUM> and a chamber orifice surface <NUM> that oppose each other and two opposing chamber minor surfaces <NUM>. The two opposing chamber minor surfaces <NUM> can each connect the chamber deflection surface <NUM> and the chamber orifice surface <NUM>. The chamber deflection surface <NUM> and the chamber orifice surface <NUM> can be planar. The chamber minor surfaces <NUM> can be concavely curved. In a cross sectional plane perpendicular to the chamber central axis C, the chamber deflection surface <NUM> and the chamber orifice surface <NUM> can be longer than the two chamber minor surfaces <NUM>.

The chamber orifice surface <NUM> includes an outlet orifice <NUM> whose purpose is described in detail later in the description. The chamber deflection surface <NUM> is located on a coolant deflection portion <NUM>, which is integrally formed with the tool body <NUM>. That is to say, the coolant deflection portion <NUM> is connected to the tool body surface <NUM> and has unitary one-piece construction therewith. Thus, the coolant chamber <NUM> is bounded on a side opposite the outlet orifice <NUM> by the coolant deflection portion <NUM>. As can be seen in <FIG>, the coolant chamber <NUM> can be recessed in the tool body surface <NUM> so that the coolant deflection portion <NUM> does not protrude from the tool body surface <NUM>. The coolant deflection portion <NUM>, or more specifically, the chamber deflection surface <NUM> serves to deflect the coolant fluid, after exiting the outlet orifice <NUM> under pressure, towards the cutting edge <NUM> of the cutting insert <NUM>.

Due to its elongated shape, the coolant chamber opening <NUM>, is configured to eject a jet of coolant having a non-circular cross-section. Furthermore, the elongated, non-circular shape of the coolant chamber opening <NUM> and the chamber deflection surface <NUM>, together are configured to direct a coolant over and along a relief surface associated with the cutting edge <NUM> such that the coolant impacts a juncture between the cutting edge <NUM> and a workpiece being cut by the cutting tool <NUM>. This results in emitting an elongated sheet of coolant through the coolant chamber opening <NUM>, such that the coolant travels over and along a relief surface of the cutting insert <NUM> and impacts at a juncture between a cutting edge <NUM> of the insert and a workpiece.

The tool body <NUM> includes at least one coolant duct 60a, 60b. The at least one coolant duct 60a, 60b acts for conveying coolant fluid to the cutting insert <NUM> via the coolant chamber <NUM>. In accordance with some embodiments of the subject matter of the present application, the tool body <NUM> can include exactly two coolant ducts, a first and second coolant duct 60a, 60b. Advantageously, this increases the amount of coolant fluid entering the coolant chamber <NUM>. In such a configuration the two coolant ducts 60a, 60b can extend on either side of the threaded bore <NUM>. It is understood that the coolant deflection portion <NUM> is located completely outside of the at least one coolant duct 60a, 60b. In the description hereinafter references are made to one coolant duct 60a but it is understood that the tool body <NUM> in accordance with the subject matter of the present application can include more than one coolant duct, where the number of coolant ducts 60a, 60b is limited by the space on the inner surfaces of the coolant chamber <NUM>.

The coolant duct 60a extends between an inlet orifice 62a and the outlet orifice <NUM>. The inlet orifice 62a is in fluid communication with a coolant source that supplies coolant fluid (not shown). The cooling fluid enters the coolant duct 60a at the inlet orifice 62a, flows along the coolant duct 60a and exits at the outlet orifice <NUM>. In this non-limiting example shown in the drawings, the coolant duct 60a is in fluid communication with a central coolant duct <NUM> and the inlet orifice 62a is located at the central coolant duct <NUM>. Likewise, when there are two coolant ducts 60a, 60b, the second coolant duct 60b is in fluid communication with the central coolant duct <NUM> at a second inlet orifice 62b located at the central coolant duct <NUM>. The coolant duct 60a opens out (terminates) in the coolant chamber <NUM>, forming the outlet orifice <NUM>. Stated differently, the coolant duct 60a intersects the coolant chamber <NUM> to form the outlet orifice <NUM>. The coolant duct 60a has a cross-section that can increase in size as it approaches the coolant chamber <NUM>.

In accordance with some embodiments of the subject matter of the present application, the outlet orifice <NUM> can be generally circular. The outlet orifice <NUM> can be located on the chamber orifice surface <NUM>. The outlet orifice <NUM> defines an outlet orifice plane P. All points on the outlet orifice <NUM> can be contained in the outlet orifice plane P. The outlet orifice <NUM> has an outlet orifice axis O which is perpendicular to the outlet orifice plane P. The coolant deflection portion <NUM> at least partially overhangs the outlet orifice <NUM> in a direction towards the insert pocket <NUM>. Specifically, in a front view of the coolant chamber <NUM>, the outlet orifice <NUM> is at least partially hidden by the coolant deflection portion <NUM>. It should be appreciated that a front view of the coolant chamber <NUM> is defined as one taken in front of the coolant chamber <NUM> in a direction along the outlet orifice axis O. As seen in <FIG>, the coolant deflection portion <NUM> can completely overhang the outlet orifice <NUM>. In such a configuration, as shown in <FIG>, the outlet orifice axis O can intersect the coolant deflection portion <NUM>.

In accordance with some embodiments of the subject matter of the present application, the chamber deflection surface <NUM> can form an external chamber deflection angle β with the outlet orifice axis O. The chamber deflection angle β can be in the range <NUM>° < β < <NUM>°. The chamber orifice surface <NUM> can be parallel to the outlet orifice plane P (i.e. form a <NUM>° angle with the outlet orifice axis O). Thus, the chamber deflection surface <NUM> and the chamber orifice surface <NUM> can taper away each other in a direction towards the coolant chamber opening <NUM>. In a similar fashion the two chamber minor surfaces <NUM> can also taper away from each other in a direction towards the coolant chamber opening <NUM>. Thus, as seen in <FIG>, as measured in a cross-sectional plane perpendicular to the chamber central axis C, the coolant chamber <NUM> can have an increasing cross-section, in a direction towards the coolant chamber opening <NUM>. Advantageously, the said tapering is intended so that the coolant fluid also has an increasing cross-section as it exits and increases in distance away from the coolant chamber opening <NUM>. The chamber central axis C can form a chamber axis angle α with the outlet orifice axis O. The chamber axis angle α can be in the range <NUM>° < α < <NUM>°. As seen in <FIG>, the chamber orifice surface <NUM> can form an obtuse internal angle with the tool body surface <NUM>. The chamber deflection surface <NUM> can form an acute internal angle with the tool body surface <NUM>.

In the configuration when the cutting tool <NUM> is a rotary cutting tool, for example a milling cutter, the cutting tool <NUM> has a central tool axis A around which the cutting tool <NUM> rotates in a direction of rotation R. The central tool axis A extends in a forward DF to rearward direction DR. The tool body <NUM> includes a forward facing body face surface <NUM> and a body periphery surface <NUM>. The body periphery surface <NUM> extends circumferentially along the central tool axis A and forms a boundary of the body face surface <NUM> at a forward end of the cutting tool <NUM>. The central tool axis A can intersect the body face surface <NUM>. The cutting tool <NUM> can include one or more axial rows of insert pockets <NUM>, seating cutting inserts <NUM>, where each cutting insert <NUM> has an associated at least one coolant chamber <NUM>.

It should be appreciated that use of the terms "forward" and "rearward" throughout the description and claims refer to a relative position in a direction of the central tool axis A towards the left and right, respectively, in <FIG>.

In accordance with one embodiment of the subject matter of the present application, the body periphery surface <NUM> constitutes the tool body surface <NUM>. In this embodiment, the cutting edge <NUM> is the cutting edge furthest from the central tool axis A. The coolant chamber opening <NUM> can be located rotationally behind the insert pocket <NUM>. Moreover, the coolant chamber opening <NUM> and the insert pocket <NUM> can be aligned in the circumferential direction of the cutting tool <NUM>. As seen in <FIG>, in accordance with another embodiment of the subject matter of the present application, the body face surface <NUM> constitutes the tool body surface <NUM>. The insert pocket <NUM> can open out to body face surface <NUM> at a forward end of the cutting tool <NUM>. In this embodiment, the cutting edge <NUM> is the axially forwardmost cutting edge. The coolant chamber opening <NUM> is angularly aligned with the insert pocket <NUM> about the central tool axis A. In both these embodiments the coolant fluid reaches the cutting edge <NUM> in a direction from the relief surface <NUM> as opposed to traditionally the rake surface <NUM> (as shown in <CIT>). Advantageously this means the coolant fluid is not obstructed by metal chips produced by the metal cutting operation. It should be understood that the cutting inserts <NUM> seated in insert pockets <NUM> in an axial forwardmost row of insert pockets <NUM> can be associated with coolant chambers <NUM> in accordance with both embodiments.

In the configuration when the cutting tool <NUM> is a turning tool, the cutting tool <NUM> has a central tool axis A, about which the cutting tool <NUM> is not configured to rotate. The central tool axis A extends in a forward DF to rearward direction DR. The tool body <NUM> includes a forward facing body face surface <NUM> and a body periphery surface <NUM>. The body periphery surface <NUM> extends circumferentially along the central tool axis A and forms a boundary of the body face surface <NUM> at a forward end of the cutting tool <NUM>. The central tool axis A can intersect the body face surface <NUM>. In accordance with this embodiment of the subject matter of the present application, the body face surface <NUM> constitutes the tool body surface <NUM>. The insert pocket <NUM> can open out to body face surface <NUM> at a forward end of the cutting tool <NUM>. The cutting edge <NUM> is the axially forwardmost cutting edge. The coolant chamber opening <NUM> is located underneath the insert pocket <NUM>.

It should be noted that one feature of the subject matter of the present application is that since the coolant deflection portion <NUM> is integrally formed with the too body <NUM> in a unitary one-piece construction there is no need to assemble the tool body <NUM> after manufacture.

It should also be noted that the coolant fluid, as it leaves the coolant chamber <NUM>, takes the form of the coolant chamber opening <NUM>. Thus, from a single coolant duct 60a, for example, a large volume of coolant fluid can be conveyed towards the cutting insert <NUM>.

It should also be further noted that it is technically impossible to manufacture a cutting tool in accordance the subject matter of the present application, by using traditional (i.e. non Additive Manufacturing) methods, since the chamber deflection portion would obstruct the drilling of the coolant duct.

Claim 1:
A tool body (<NUM>) comprising a tool body surface (<NUM>) and an insert pocket (<NUM>) for seating of a cutting insert (<NUM>), recessed therein; wherein:
the tool body (<NUM>) comprises:
a coolant chamber (<NUM>) that opens out to the tool body surface (<NUM>) at a coolant chamber opening (<NUM>); and
at least one coolant duct (60a, 60b) that opens out at an outlet orifice (<NUM>) in the coolant chamber (<NUM>); wherein:
the coolant chamber (<NUM>) is bounded on a side opposite the outlet orifice (<NUM>) by a coolant deflection portion (<NUM>) that is integrally formed with the tool body (<NUM>) in a unitary one-piece construction and at least partially overhangs the outlet orifice (<NUM>) in a direction towards the insert pocket (<NUM>);
characterised in that the coolant chamber opening (<NUM>) is spaced apart from the insert pocket (<NUM>); and in that
the coolant chamber opening (<NUM>) is elongated and non-circular.