Rotary cutting tool having tool holder with conical internal thread and replaceable cutting head with straight external thread, and said tool holder

Patent metadata

Field	Value
Publication number	US-10105771-B2
Application number	US-201615075782-A
Country	US
Kind code	B2
Filing date	Mar 21, 2016
Priority date	Mar 21, 2016
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A rotary cutting tool includes a replaceable cutting head and a tool holder. The replaceable cutting head includes a forward cutting portion and a rearward mounting portion. The mounting portion includes a male coupling member that includes a straight external thread. The tool holder includes a female coupling member that includes a conical internal thread. When the rotary cutting tool is in a locked position, the external thread is threadingly engaged with the internal thread.

First claim

What is claimed is:

1. A rotary cutting tool ( 20 ) having a longitudinal axis (L) and extending in a forward (D F ) to rearward direction (D R ), comprising:
a tool holder ( 24 ), having a holder longitudinal axis (C) and comprising a female coupling member ( 68 ) having an internal thread ( 72 ) extending rearwardly from a holder forward surface ( 70 ), the holder forward surface ( 70 ) extending transversely with respect to the holder longitudinal axis (C); and
a replaceable cutting head ( 22 ) having a head longitudinal axis (A) and comprising:
a forward portion forming a cutting portion ( 26 ); and
a rearward portion forming a mounting portion ( 28 ), the mounting portion ( 28 ) comprising a male coupling member ( 38 ) having an external thread ( 42 ) and protruding rearwardly from a head base surface ( 40 ), the head base surface ( 40 ) extending transversely with respect to the head longitudinal axis (A), and defining a boundary between the cutting portion ( 26 ) and the mounting portion ( 28 );

wherein:
the external thread ( 42 ) of the male coupling member ( 38 ) is a straight thread whose thread ridge extends about a cylinder;
the internal thread ( 72 ) of the female coupling member ( 68 ) is conical thread; and
the rotary cutting tool ( 20 ) is adjustable between:
a released position in which the male coupling member ( 38 ) is located outside of the female coupling member ( 68 ), and the internal and external threads ( 42 , 72 ) are not threadingly engaged to one another, and
a locked position in which the male coupling member ( 38 ) is removably retained in the female coupling member ( 68 ) with the internal and external threads ( 42 , 72 ) threadingly engaged to one another.

2. The rotary cutting tool ( 20 ) according to claim 1 , wherein
the internal thread ( 72 ) comprises an internal thread ridge ( 74 ), extending helically about an internal thread axis (D), and comprising forward and rearward internal flank surfaces ( 76 , 78 ) and an internal top surface ( 80 ) extending therebetween;
the forward and rearward internal flank surfaces ( 76 , 78 ) face in opposite axial directions (D F , D R ) and delimit a helical internal thread groove ( 82 ) that comprises an internal bottom surface ( 84 ); and
in the released position:
at least one of the internal thread ridge ( 74 ) and the internal thread groove ( 82 ) extend about a respective cone (K) having a cone angle (γ); and
the cone angle (γ) is in the range of 0.02°≤γ≤1.6°.

3. The rotary cutting tool ( 20 ) according to claim 2 , wherein the cone angle (γ) is equal to exactly 0.8°.

4. The rotary cutting tool ( 20 ) according to claim 2 , wherein only the internal thread groove ( 82 ) extends about a respective cone (K).

5. The rotary cutting tool ( 20 ) according to claim 4 , wherein the internal thread ridge ( 74 ) extends about a cylinder (Y).

6. The rotary cutting tool ( 20 ) according to claim 2 , wherein in a cross-sectional view taken in an axial plane containing the internal thread axis (D):
the internal top surface ( 80 ) forms a plurality of internal thread crests ( 88 ) that are parallel to the internal thread axis (D) and co-linear with each other; and
the internal bottom surface ( 84 ) forms a plurality of internal thread roots ( 90 ) that are parallel to the internal thread axis (D) and follow a pattern of decreasing distance therefrom in the rearward direction (D R ).

7. The rotary cutting tool ( 20 ) according to claim 2 , wherein the forward and rearward internal flank surfaces ( 76 , 78 ) are offset from the internal thread axis (D) by a distance that decreases as the internal ridge ( 74 ) extends helically about the internal thread axis (D) in the rearward direction (D R ).

8. The rotary cutting tool ( 20 ) according to claim 2 , wherein:
the external thread ( 42 ) comprises an external thread ridge ( 44 ), extending helically about an external thread axis (B), and comprising forward and rearward external flank surfaces ( 46 , 48 ) and an external top surface ( 50 ) extending therebetween;
the forward and rearward external flank surfaces ( 46 , 48 ) face in opposite axial directions (D F , D R ) and delimit a helical external thread groove ( 52 ) that comprises an external bottom surface ( 54 );
the forward external flank surface ( 46 ) and the forward internal flank surface ( 76 ) face in the forward direction (D F );
the rearward external flank surface ( 48 ) and the rearward internal flank surface ( 78 ) face in the rearward direction (D R ); and
in the locked position, the rearward internal flank surface ( 78 ) abuts the forward external flank surface ( 46 ).

9. The rotary cutting tool ( 20 ) according to claim 8 , wherein in the locked position:
the forward internal flank surface ( 76 ) is spaced apart from the rearward external flank surface ( 48 );
the internal top surface ( 80 ) is spaced apart from the external bottom surface ( 54 ); and
the internal bottom surface ( 84 ) is spaced apart from the external top surface ( 50 ).

10. The rotary cutting tool ( 20 ) according to claim 8 , wherein in a cross-sectional view taken in an axial plane containing the external thread axis (B):
the external top surface ( 50 ) forms a plurality of external thread crests ( 56 ) that are parallel to the external thread axis (B) and co-linear with each other; and
the external bottom surface ( 54 ) forms a plurality of external thread roots ( 58 ) that are parallel to the external thread axis (B) and co-linear with each other.

11. The rotary cutting tool ( 20 ) according to claim 1 , wherein in a cross-sectional view taken in an axial plane containing the head longitudinal axis (A), the external thread ( 42 ) defines an external thread form ( 60 ) that is trapezoidal.

12. The rotary cutting tool ( 20 ) according to claim 1 , wherein in a cross-sectional view taken in an axial plane containing the holder longitudinal axis (C), the internal thread ( 72 ) defines an internal thread form ( 86 ) that is trapezoidal.

13. The rotary cutting tool ( 20 ) according to claim 1 , wherein:
the external thread ( 42 ) comprises an external thread ridge ( 44 ), extending helically about an external thread axis (B), and comprising forward and rearward external flank surfaces ( 46 , 48 ) and an external top surface ( 50 ) extending therebetween;
the forward and rearward external flank surfaces ( 46 , 48 ) face in opposite axial directions (D F , D R ) and delimit a helical external thread groove ( 52 ) that comprises an external bottom surface ( 54 );
the forward external flank surface ( 46 ) and the forward internal flank surface ( 76 ) face in the forward direction (D F );
the rearward external flank surface ( 48 ) and the rearward internal flank surface ( 78 ) face in the rearward direction (D R );
in the locked position:
the rearward internal flank surface ( 78 ) abuts the forward external flank surface ( 46 );
the forward internal flank surface ( 76 ) is spaced apart from the rearward external flank surface ( 48 );
the internal top surface ( 80 ) is spaced apart from the external bottom surface ( 54 ); and
the internal bottom surface ( 84 ) is spaced apart from the external top surface ( 50 ); and

frictional engagement between the external thread ( 42 ) and the internal thread ( 72 ) increases in a direction from a forwardmost turn of the external thread ( 42 ) towards the rearmost turn of the external thread ( 42 ).

14. A tool holder ( 24 ), having a holder longitudinal axis (C) extending in the forward (D F ) to rearward direction (D R ), comprising a female coupling member ( 68 ) having an internal thread ( 72 ) ext

Assignees

• Iscar Ltd

Inventors

• Guy Hanoch

Classifications

• B23C2265/08

  Conical · CPC title

• B23C2240/32

  Connections using screw threads · CPC title

• B23C2210/03

  Cutting heads comprised of different material than the shank irrespective of whether the head is detachable from the shank · CPC title

• B23C2210/02

  Connections between the shanks and detachable cutting heads · CPC title

• B23C5/109

  with removable cutting inserts · CPC title