Title of Invention

A ROTARY CUTTING TOOL AND A METHOD OF ASSEMBLING THE ROTARY SUTTING TOOL

Abstract A rotary cutting tool (10, 110) comprising a cutting head (16, 116), a screw member (18, 118) and a tool shank (20). The cutting head (16, 116), has an axially directed through bore (27, 127) with locking wings (30, 130) protruding from the bore surface (28, 128). Each locking wing having a sloping locking surface (34, 134) and stopper (36, 136) with a stop surface (40, 140). The screw member (18, 118) outwardly radially protruding clamping wings (66, 166), each having a sloping clamping surface (70, 170) and an associated side abutment surface (71", 175"). The screw member is in threaded engagement with the tool shank, with the clamping wings and locking wings aligned in pairs with the locking and clamping surfaces (34, 70; 134, 170) of each pair in abutment and with each stop surface (40, 140) is in abutment with a given side abutment surface (71", 175").
Full Text FIELD OF THE INVENTION
The present invention relates in general to rotary metal cutting
tools, and specifically to reamers having replaceable cutting heads.
BACKGROUND OF THE INVENTION
A reamer of this type is disclosed in US Patent 4,040,765. In this
design the reamer has an interchangeable cutter head with a conical butt which is
inserted in a matching conical socket in the reamer shank. The cutter head is
screwed to the reamer shank via a screw bolt. The conical engagement between
the cutter head and the reamer shank ensures a connection free from play.
However, this arrangement has the drawback that, particularly in the case of
fairly strong feeding forces, the cutter head is pressed into the reamer shank and
jams, especially because the conical engagement is also self-locking. The cutter
head is hard to remove from the reamer shank, whereby the union pin in
particular is subjected to great wear and tear. In this reamer there is no provision
for equipping the cutter heads with coolant means. It is also not evident haw
coolant means could be incorporated in this reamer, especially not coolant means
having exits adjacent the cutting edges. Furthermore, since the conical butt has
an internal thread the cutting head and conical butt cannot be made as a one piece
integral member by form pressing and sintering a carbide powder.
Another example of such a reamer disclosed in US Patent
5,163,790 . The reamer has an interchangeable cutter head and a coolant-
lubricant feed supplying the cutter head from an annular nozzle disposed far from
the cutting blades. The cutter-head shank is cylindrical and is retained in an
opening of the reamer shank and is secured threrto by means of a clamping bolt
passing through the cutter head. The clamping bolt includes a recessed hexagon
by means of which the clamping bolt can be screwed in and out. To replace the
cutter head the clamping bolt has to be disadvantageously completely removed
from the reamer shank. In this reamer there is no provision leading coolant to the
cutter head. Moreover, when replacing a cutter head and tightening the clamping
bolt to secure the cutter-head in position, there is no guarantee that the clamping
bolt will end up in the same rotationally oriented position each time. Therefore,
even if the coolant were to be somehow supplied to the head of the bolt and
radially directed coolant apertures were provided in the head of the bolt, it would
not be certain that the apertures would aligned with the cutter-head cutting edges
every time a cutter head was secured in position. Furthermore, if instead of
cutter blades secured to the cutter head, it was desired to form a one piece
integral cutter head and shank from solid carbide, the elongated form of the
cutter head together with the cutter-head shank makes it very difficult to form
press and sinter.
It is an object of the present invention to provide a cutting tool and a
replaceable cutting head therefor that significantly reduces or overcomes the
aforementioned disadvantages.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a rotary
cutting tool having a forward end and a rearward end and a longitudinal axis A
passing through the forward and rear ends, the cutting tool comprising a cutting
head, a screw member and a tool shank;
the cutting head comprising a generally cylindrical main body portion and a
rearwardly extending conical portion, and an axially directed through bore
having a bore surface; a plurality of axially extending and inwardly radially
protruding locking wings each with a sloping locking surface is formed on the
bore surface; an axially extending stopper having a tangentially facing stop
surface, protrudes from each locking wing;
the screw member comprises a plurality of axially extending and outwardly
radially protruding clamping wings on a forward end thereof and an external
screw thread rearward of the clamping wings, each clamping wing has a sloping
clamping surface, and each clamping wing has an associated side abutment
surface;
the tool shank has a receiving bore opening to a forward end thereof and
comprising a conical forward portion and an internally threaded portion rearward
of the conical portion;
wherein,
the external screw thread of the screw member is in threaded engagement
with the internally threaded portion of the tool shank, the conical portion of the
cutting head is located within the conical portion of the tool shank, the clamping
wings and locking wings are aligned in pairs with the locking and clamping
surfaces of each pair in abutment, and with each stop surface in abutment with a
given side abutment surface.
In accordance with a first embodiment of the present invention, the
stopper is located at a forward end or the locking wing.
Typically, the stopper protrudes from the locking surface.
Further in accordance with the first embodiment of the present
invention, the given side abutment surface is at least a portion of a side surface of
the clamping wing.
In accordance with a second embodiment of the present invention, the
stopper is located at a rear end of the locking wing
Further in accordance with the second embodiment of the present
invention, the given side abutment surface is at least a portion of a side surface of
a radial abutment member.
Preferably, the radial abutment member is located adjacent the
external screw thread.
Further preferably, an axial abutment member is located between
consecutive radial abutment members.
In accordance with the present invention, the tool shank has a channel
communicating with a screw member bore, which screw member bore
communicates with radially directed coolant outlets adjacent a forward end of the
screw member, the coolant outlets being aligned with recesses in the cutting
head, the recesses being adjacent cutting edges of the cutting head.
Further in accordance with the present invention, the screw member
has resilient members extending from the external screw thread to a rearward end
of the screw member.
In accordance with a specific application of the present invention, the
rotary cutting tool is a reamer.
There is also provided in accordance with the present invention, a
method of assembling the rotary cutting tool of the present invention, comprising
the steps of:
positioning the screw member in the receiving bore until the external screw
thread is in initial threaded engagement with the internally threaded portion;
placing the cutting head over the screw member with the locking wings
passing between the clamping wings;
rotating the cutting head until the locking wings and the clamping wings are
axially aligned in pairs and the stop surfaces abut the side abutment surfaces; and
further rotating the cutting head until the locking and clamping surfaces of
each pair of locking and clamping wings are in abutment and the screw member
is fully screwed into the internally threaded portion thereby securing the cutting
head to the tool shank.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
For a better understanding, the invention will now be described, by
way of example only, with reference to the accompanying drawings in which:
Fig. 1 is a perspective view of a rotary cutting tool in accordance with a
first embodiment of the present invention;
Fig. 2 is an exploded perspective of the rotary cutting tool in Fig. 1;
Fig. 3 is a longitudinal cross-sectional view of the rotary cutting tool in
Fig. 1;
Fig. 4 is a top view of the cutting head of the rotary cutting tool shown in
Fig. 1;
Fig. 5 is a cross-sectional view of the cutting head taken along the line V-
V in Fig. 4;
Fig. 6 is a cross-sectional view of the cutting head taken along the line VI-
VI in Fig. 4;
Fig. 7 is a side view of the screw member in Fig.2;
Fig. 8 is a top view of the screw member in Fig.2;
Fig. 9 is a longitudinal cross-sectional view of the tool shank in Fig. 1;
Fig. 10 is a cross-section of the cutting head and screw member taken
along the line X-X in Fig. 3with the cutting head in an open position;
Fig. 11 is a side view of a screw member of a rotary cutting tool in
accordance with a second embodiment of the present invention;
Fig. 12 is a bottom view of a cutting head of the rotary cutting tool in
accordance with the second embodiment of the present invention;
Fig. 13 is a cross sectional view of the cutting head of the rotary cutting
tool in accordance with the second embodiment of the present invention, taken
along the line XIII-XIII in Fig. 12; and
Fig. 14 is a cross sectional view of the screw member in Fig. 11, taken
along the line XIV-XTV.
DETAILED DESCRIPTION OF THE INVENTION
Attention is first drawn to Figs. 1-3 showing a cutting tool in
accordance with a first embodiment of the present invnetion illustrated by means
of a reamer 10. The reamer 10 has a forward end 12, a rearward end 14 and a
longitudinal axis of rotation A passing through the forward and rearward ends
12,14 defining a forward to rearward direction. The reamer 10 comprises a
cutting head 16, a screw member 18, and a tool shank 20. The cutting head 16 is
a form pressed and sintered hard metal body made from a carbide powder such as
Tungsten Carbide. The screw member 18 and the tool shank 20 are formed of
machined steel or other hard materials. The tool shank 20 has an axially directed
coolant channel 22 for providing coolant to the cutting head 16.
The cutting head 16, shown in Figs. 4-6, has a forward end 24, a
rearward end 26, an axis of rotational symmetry B, and an axially directed
cutting head bore 27 having a bore surface 28. When securing the cutting head
16 to the tool shank 20, the cutting head 16 is rotated clockwise around the axis
B, when viewed in a top view. In the following, the terms "leading" and
"trailing" will be used with respect to clockwise rotation of the cutting head 16.
A bore radius Rl is defined between the axis of rotational symmetry B and the
bore surface 28. The bore surface 28 has protruding from it, adjacent the
rearward end 26 of the cutting head 16, three identical integrally formed radially
inwardly projecting locking wings 30, each having a locking wing radial
dimension R2 defined between an innermost surface 31 of the locking wings 30
and the axis of rotational symmetry B, wherein the locking wing radial
dimension R2 is less than the bore radius R1. The locking wings 30 are equally
spaced on the bore surface 28 about the axis of rotational symmetry B. Adjacent
locking wings 30 are separated by locking wing gaps 32. Each locking wing 30
has a generally forwardly facing sloping locking surface 34. A stopper 36
protrudes from a forward end 35' of each locking wing 30, protruding in the axial
direction from the locking surface 34, on a trailing side thereof. The stopper 36
has a generally radially extending, tangentially facing, first stop surface 38 on its
trailing side and a generally radially extending, tangentially facing, second stop
surface 40 on its leading side. The first and second stop surfaces 38, 40 are
generally transverse to the locking surface 34 and preferably normal, or
substantially normal, thereto. In a top view, the locking wing 30 has a first
angular extent 42 defined by the locking surface 34. The stopper 36 has a second
angular extents 44 that is smaller than the first angular extents 42. The first and
second angular extent 42, 44 combine to form the total angular extent 45 of a
single locking wing 30. The locking wing gap 32 has a third angular extent 46.
A conical portion 48 projects at the rearward end 26 of the cutting
head 16 from a generally cylindrical main body portion 49 of the cutting head 16.
The conical portion 48 has an outer conical surface 50 coaxially aligned with the
axis of rotational symmetry B and tapering rearwardly to a rearwardly facing
annular contact surface 48'. The outer conical surface 50 merges with the cutting
head 16 via a step 51 formed by the outer conical surface 50 and a rearwardly
facing planar annular abutment surface 52 of the main body portion 49 of the
cutting head 16.
The cutting head 16 has a crown-like structure at its forward end 24
having six identical equally spaced cutting edges 54 and recesses 56, each recess
56 being substantially adjacent an associated cutting edge 54. A key (not shown)
having protrusions that match the recesses 56, mates with the forward end 24 of
the cutting head 16 in order to rotate the cutting head 16 during assembly, or
disassembly of the reamer 10.
Attention is now drawn to Figs. 7 and 8, showing the screw
member 18. The screw member 18 has a forward end 58, a rearward end 60, a
longitudinal axis C, and a generally tube-like body having a peripheral surface 62
and an axially directed screw member bore 64 open at the rearward end 60. The
peripheral surface 62 has a peripheral radial dimension R3 defined between the
longitudinal axis C and the peripheral surface 62, wherein the peripheral radial
dimension R3 is less than the locking wing radial dimension R2. The screw
member 18 has three identical clamping wings 66 located towards its forward
end 58. The clamping wings 66 protrude radially outwardly from the peripheral
surface 62 at a maximum clamping wing radial dimension R4 with respect to the
axis of rotational symmetry B, wherein the maximum clamping wing radial
! dimension R4 is greater than the locking wing radial dimension R2, but less than
the bore radius Rl. The clamping wings 66 are equally spaced apart about the
longitudinal axis C, with adjacent clamping wings 66 separated by clamping
wing gaps 68. Each clamping wing gap 68 is substantially equal in angular
extent to the total angular extent 45 of each locking wing 30. Each clamping
wing 66 has an angular extent with respect to the longitudinal axis C
substantially less than the angular extent of each locking wing gap 32. Each
clamping wing 66 has a sloping slightly convex, outwardly and rearwardly facing
clamping surface 70 and first and second opposing generally radially extending
side abutment surfaces 71'3 71".
The screw member 18 is has an external screw thread 72 towards
its rearward end 60 and four resilient members 74, extending from the external
screw thread 72 to the rearward end 60. The resilient members 74 give the
rearward end 60 a degree of flexibility in the radial direction. An abutment ring
76 projects radially outwardly from the screw member 18 at a location between
the clamping wings 66 and the external screw thread 72, preferably adjacent
thereto. At the forward end of the screw member 18 are six radially directed
coolant outlets 78 communicating between the screw member bore 64 and the
peripheral surface 62.
Attention is now drawn to Fig. 9, showing the forward end 80 of
the tool shank 20, which is has a receiving bore 82, a planar forwardly facing
annular support surface 84, a longitudinal axis D, and the coolant channel 22
extending rearwardly from the receiving bore 82. The receiving bore 82 and the
coolant channel 22 are coaxially aligned with the longitudinal axis D. The
receiving bore 82 has a rearwardly tapering conical forward portion 86, and an
internally threaded portion 88 extends from the conical forward portion 86 to a
resisting portion 90. The resisting portion 90 has a diameter slightly smaller than
the diameter of the rearward end 60 of the screw member 18.
The assembly of the reamer 10 is performed by placing the
rearward end 60 of the screw member 18 within the receiving bore 82 of the tool
shank 20 and bringing the external screw thread 72 into initial threading
engagment with the internally threaded portion 88. The cutting head 16 is placed
upon the screw member 18 with the rearward end 26 of the cutting head 16 over
the forward end 58 .of the screw member 18, until the annular contact surface 48'
of the conical portion 48 of the cutting head 16 abuts the abutment ting 76. In
this position, the cutting head 16 will be referred to as being in an open-position,
as shown in Fig. 10. In the open-position, the clamping wings 66 lie in the
locking wing gaps 32 of the cutting head 16 and the locking wings 30 lie in the
clamping wing gaps 68 of the screw member 18.
In order to secure the cutting head 16 to the tool shank 20, the
cutting head 16 is now rotated in a clockwise direction about the axis of
rotational symmetry B, when the cutting head 16 is viewed in the top view. The
resilient members 72 engage the resisting portion 90 restraining the screw
member 18 from freely rotating. The cutting head 16 is rotated from the open
position, until each locking wing 30 slides underneath a corresponding clamping
wing 66 with the locking and clamping surfaces 34, 70 in abutment, and each
second stop surface 40 of the stoppers 36 abuts a corresponding clamping wing
66 at the second side abutment surface 71" thereof. As the cutting head 16 is
further rotated, the screw member 18 rotates with it due to the engagement of the
second stop surface 40 and the second side abutment surface 71" of the clamping
wing 66, thereby securing the screw member 18 in the threaded portion 88. With
abutment between the clamping surface 70 and the locking surface 34 being
maintained, the screw member 18 pulls the conical portion 48 of the cutting head
16 into the conical forward portion 86 of the tool shank 20 until the annular
abutment surface 52 of the cutting head 16 is brought into engagement with the
annular support surface 84 of the tool shank 20. With the conical portion 48 of

the cutting head 16 located in the conical forward portion 86 of the tool shank 20,
the cutting head 16 is centered with respect to the tool shank 20.
It should be noted that the cutting head 16 does not have a threaded
portion. Instead, the threading is located on the screw member 18, thereby
effectively decoupling any adverse effects that the threading can have on the
centering of the cutting head 16. As mentioned above, the clamping surface 70
of each clamping wing 66 is slightly convex, thereby ensuring that the screw
member 18 "floats" as the cutting head 16 is rotated clockwise in order to
securely clamp the cutting head 16 in position. Surface contact by the clamping
wings 66 and the locking wings 30 is designed not to affect the centering of the
cutting head 16 formed by location of the conical portion 48 of the cutting head
16 in the conical forward portion 86 of the tool shank 20. The coolant outlets 78
are spatially distributed with respect to the clamping wings 66 in such a manner
mat when the reamer 10 is assembled, the recesses 56 are aligned with the
coolant outlets 78, thus ensuring that the coolant is supplied directly to each of
the cutting edges 54. The alignment of the coolant outlets 78 with the recesses
56 is made possible due to the fact that the second stop surface 40 of each
stopper 36 abuts a corresponding second side abutment surface 71" of each
clamping wing 66.
To unclamp the cutting head 16 and remove it from the tool shank
20, the cutting head 16 is rotated in an anticlockwise direction. Initially, the
cutting head 16 will rotate until the first stop surfaces 38 abut the first side
abutment surfaces 71' of the clamping wings 66, thereby unscrewing the screw
member 18. As the screw member 18 exits the receiving bore 82, the abutment
ring 76 pushes up on the conical portion 48 of the cutting head 16 forcing it out
of the conical forward portion 86 of the receiving bore 82. At this stage, the
cutting head 16 can be lifted off of the screw member 18 and a new cutting head
16 can be placed in position on the screw member 18. Hence, in normal
operation, the, screw member 18 does not have to be removed; it is simply
screwed in and out of the receiving bore 82 by a few turns every time a cutting
head 16 is replaced. If it is required to remove the screw member 18, that is, to
disassemble the reamer 10, then one simply continues to rotate the cutting head
16 in an anticlockwise direction until the screw member 18 is completely
unscrewed.
As described above, in accordance with the first embodiment of the
present invention," rotational coupling between the cutting head and the screw
member is obtained by the engagement of the clamping wings 66 of the screw
member 18 and the stoppers 36 which protrude forwardly in the axial direction
from the locking surfaces 34 of the locking wings 30. When the cutting head 16
is attached to the tool shank 20, each locking wing 30 is located underneath a
corresponding clamping wing 66 with the locking and clamping surfaces 34, 70
in abutment.
Attention is now drawn to Figs. 11 to 14 showing a cutting head
116, a screw member 118 and the tool shank 20 of a reamer 110 in accordance
with a second embodiment of the present invention. The reamer 110 according
to the second embodiment is not shown, but is identical in appearance to the
reamer 10 in accordance with the first embodiment, as shown in Fig. 1. The tool
shank 20 of the reamer 110 according to the second embodiment is identical to
the tool shank 20 of the first embodiment. The assembly and disassembly of the
reamer 110 in accordance with the second embodiment and the securing of the
cutting head 116 to, and removal from, the tool shank 20, is procedurally the
same as in the first embodiment. Therefore, the description of the reamer 110 in
accordance with the second embodiment will focus principally on the differing
features between the two embodiments.
The cutting head 116 has a forward end 124, a rearward end 126,
an axis of rotational symmetry B1, and an axially directed cutting head bore 127
having a bore surface 128. The bore surface 128 has protruding from it, adjacent
the rearward end 126 of the cutting head 116, three identical integrally formed
radially inwardly projecting locking wings 130. The locking wings 130 are
equally spaced about the axis of rotational symmetry Bl on the bore surface 128
and have locking wing gaps 132 between adjacent locking wings 130. Each
locking wing 130 has a generally forwardly facing sloping locking surface 134
and a stopper 136 located at the rear end 135" of the locking wing 130. The
stopper 136 protrudes in the axial direction from the rear end 135", on a trailing
side thereof. The stopper 136 has a radially extending, generally tangentially
facing, first stop surface 138 on its trailing side and a radially extending,
. generally tangentially facing, second stop surface 140 on its leading side.
A conical portion 148 projects at the rearward end 126 of the
cutting head 116 from a generally cylindrical main body portion 149 of the
cutting head 116. The conical portion 148 has an outer conical surface 150
coaxially aligned with the axis of rotational symmetry Bl that tapers rearwardly
to a rearwardly facing annular contact surface 148'. The outer conical surface
150 merges with the cutting head 116 at a step 151 formed by the outer conical
surface 150 and a rearwardly facing planar annular abutment surface 152 of the
cylindrical main body portion 149 of the cutting head 116. The external
appearance of the cutting head 116 in accordance with the second embodiment is
identical to that of the first embodiment. The cutting head 116 having a crown-
like structure at its forward end 124 having six identical equally spaced cutting
edges 154 (not seen in Figs. 12 and 13) and recesses 156, each recess 156 being
substantially adjacent an associated cutting edge 154.
The screw member 118 has a forward end 158, a rearward end 160,
a longitudinal axis C1, and a generally tube-like body having a peripheral surface
162 and an axially directed screw member bore 164 open at its rearward end 160.
The screw member 118 has three identical clamping wings 166 located towards
its forward end 158. The clamping wings 166 protrude radially outwardly from
the peripheral surface 162 and are equally spaced apart about the longitudinal
axis Cl, having clamping wing gaps 168 between them. Each clamping wing
166 has a sloping, preferably slightly convex, outwardly and rearwardly facing
clamping surface 170 and first and second generally radially extending side
surfaces 171', 171".
The screw member 118 has an external screw thread 172 located
towards its rearward end 160 and four resilient members 174, extending from the
external screw thread 172 to the rearward end 160 thereby providing the
rearward end 160 a degree of flexibility in the radial direction. Radial abutment
members 175, protruding radially outwardly from the peripheral surface 162, are
located between the external screw thread 172 and the clamping wings 166
adjacent the external screw thread 172. The radial abutment members 175 are
spaced equally around the peripheral surface 162 with an axial abutment member
176 located between each radial abutment member 175. Each radial abutment
member 175 has first and second side abutment surfaces 175', 175". Each axial
abutment member 176 has an axially and forwardly facing axial abutment surface
176'. The screw member 118 has six radially directed coolant outlets 178
adjacent the forward end 158, communicating between the screw member bore
164 and the peripheral surface 162. As with the first embodiment, in the second
embodiment the coolant outlets 178 are spatially distributed with respect to the
clamping wings 166 in such a manner that when the reamer 110 is assembled, the
recesses 156 are aligned with the coolant outlets 178, thus ensuring that the
coolant is supplied directly to each of the cutting edges 154.
The reamer 110, in accordance with the second embodiment of the
present invention, is assembled much in the same way as the reamer 10 in
accordance with the first embodiment. The rearward end 160 of the screw
member 118 is placed in coaxial alignment within the receiving bore 82 of the
tool shank 20, so that the external screw thread 172 is in initial threading
engagement with the internally threaded portion 88 of the tool shank 20. The
cutting head 116 is placed upon the screw member 118 with the rearward end
126 of the cutting head 16 over the forward end 158 of the screw member 118,
and the rearwardly facing annular contact surface 148' of the conical portion 148
is in abutment with the forwardly facing axial abutment surfaces 176' of the axial
abutment members 176. In this position, referred to the "open-position", the
clamping wings 166 lie in the locking wing gaps 132 of the cutting head 116 and
the locking wings 130 lie in the clamping whig gaps 168 of the screw member
118.
In order to secure the cutting head 116 to the tool shank 20, the
cutting head 116 is now rotated in a clockwise direction about the axis of
rotational symmetry B, when the cutting head 116 is viewed in a top view. The
cutting head 116 is rotated from the open position, until each locking wing 130
slides underneath an opposing clamping wing 166 so that the locking wings 130
and clamping wings 166 form opposing wing pairs. In each wing pair, the
clamping surface 170 of the clamping wing 166 is in abutment with the locking
surface 134 of the locking wing 130. In this position, the stoppers 136 and the
radial abutment members 175 form radial abutment pairs. In each radial
abutment pair, the second stop surface 140 of the stopper 136 is in abutment with
the second side abutment surface 175" of the radial abutment member 175. The
cutting head 116 is rotated until the screw member 118 is completely screwed
into in the threaded portion 88 and the conical portion 148 of the cutting head
116 is located in a conical forward portion 86 of the tool shank 20 with the
annular abutment surface 152 of the cutting head 116 in engagement with an
annular support surface 84 at a forward end of the tool shank 20.
To unclamp the cutting head 116 and remove it from the tool shank
20, the cutting head 116 is rotated in an anticlockwise direction. Initially, the
cutting head 116 will rotate until the first stop surfaces 138 abut the first side
abutment surfaces 175' of the radial abutment members 175, thereby unscrewing
the screw member 118. As the screw member 118 exits the receiving bore 82,
the forwardly facing axial abutment surfaces 176' of the axial abutment members
176 push up on the annular contact surface 148' of the conical portion 148 of the
cutting head 116 forcing it out of the receiving bore 82.
Although the present invention has been described to a certain
degree of particularity, it should be understood that various alterations and
modifications could be made without departing from the spirit or scope of the
invention as hereinafter claimed.

WE CLAIM
1. A rotary cutting tool (10, 110) having a forward end (12) and
a rearward end (14) and a longitudinal axis (A) passing
through the forward and rear ends, the cutting tool
comprising a cutting head (16, 116), a screw member (18,
118) and a tool shank (20); the cutting head (16, 116)
comprising a generally cylindrical main body portion (49, 149)
and a rearwardly extending conical portion (48, 148) and an
axially directed through bore (27, 127) having a bore surface
(28, 128); a plurality of axially extending and inwardly
radially protruding locking wings (30, 130) each having a
sloping locking surface (34, 134) protrudes from the bore
surface (28, 128); the screw member (18, 118) comprises a
plurality of axially extending and outwardly radially protruding
clamping wings (66, 166) on a forward end (58, 158) thereof
and an external screw thread (72, 172) rearward of the
clamping wings (66, 166) each clamping wing has a stopping
camping surface (70, 170) and each clamping wing has an
associated side abutment surface (71", 175"); the tool shank
(20) has a receiving bore (82) opening to a forward end (80)
thereof and comprising a conical forward portion (86) and an
internally threaded portion (88) rearward of the conical
portion (86) wherein the external screw thread (72, 172) of
the screw member (18, 118) is in threaded engagement with
the internally threaded portion (88) of the tool shank (20),
the clamping wings (66, 166) and locking wings (30, 130) are
aligned in pairs with the locking and clamping surfaces (34,
70; 134, 170) of each pair in abutment, characterized in that
an axially extending stopper (36, 136) having a tangentially
facing stop surface (40, 140) protrudes from each locking
wing (30, 130), the conical portion (48, 148) of the cutting
head (16, 116) is located within the conical portion (86) of
the tool shank (20) and each stop surface (40, 140) is in
abutment with a given side abutment surface (71", 175").
2. The rotary cutting tool (10, 110) as claimed in claim 1,
wherein the stopper (36) is located at a forward end (35') of
the locking wing (30).
3. The rotary cutting tool (10, 110) as claimed in claim 2,
wherein the stopper (36) protrudes from the locking surface
(34).
4. The rotary cutting tool (10, 110) as claimed in claim 3,
wherein the given side abutment surface (71") is at least a
portion of a side surface of the clamping wing (66).
5. The rotary cutting tool (10, 110) as claimed in claim 1,
wherein the stopper (136) is located at a rear end of the
locking wing (130).
6. The rotary cutting tool (10, 110) as claimed in claim 5,
wherein the given side abutment surface (175") is at least a
portion of a side surface of a radial abutment member (175).

7. The rotary cutting tool (10, 110) as claimed in claim 6,
wherein the radial abutment member (175) is located
adjacent the external screw thread (172).
8. The rotary cutting tool (10, 110) as claimed in claim 5,
wherein an axial abutment member (176) is located between
consecutive radial abutment members (175).
9. The rotary cutting tool (10, 110) as claimed in any one of
claims 1 to 8, wherein the tool shank (20) has a channel (22)
communicating with a screw member bore (64, 164), which
screw member bore (64, 164) communicates with radially
directly coolant outlets (78, 178) adjacent a forward end (58,
158) of the screw member (18, 118), the coolant outlets (78,
178) being aligned with recesses (56, 156) in the cutting
head (16, 116), the recesses (56, 156) being adjacent cutting
edges (54, 154) of the cutting head (16, 116).
10. The rotary cutting tool (10, 110) as claimed in any one of
claims 1 to 9, wherein the screw member (18, 118) has
resilient members (74, 174) extending from the external
screw thread (72, 172) to a rearward end (60, 160) of the
screw member (18, 118).
11. The rotary cutting tool (10, 110) as claimed in claim 10,
wherein the rotary cutting tool is a reamer.
12. A method of assembling a rotary cutting tool as claimed in
claims 1 to 11, comprising the steps of:
positioning the screw member (18, 118) in the receiving
bore (82) until the external screw thread (72, 172) is in
initial threaded engagement with the internally
threaded portion (88);
placing the cutting head (16, 116) over the screw
member (18, 118) with the locking wings (30, 130)
passing between the clamping wings (66, 166);
rotating the cutting head (16, 116) until the locking
wings (30, 130) and the clamping wings (66, 166) are
axially aligned in pairs and the stop surfaces (40, 140)
abut the side abutment surfaces (71", 175"); and
further rotating the cutting head (16, 1160 until the
locking and clamping surfaces (34, 70; 134, 170)of
each pair of locking and clamping wings (30, 66; 130,
166) are in abutment and the screw member (18, 118)
is fully screwed into the internally threaded portion (88)
thereby securing the cutting head (16, 116) to the tool
shank (20).
A rotary cutting tool (10, 110) comprising a cutting head (16, 116), a screw
member (18, 118) and a tool shank (20). The cutting head (16, 116), has an
axially directed through bore (27, 127) with locking wings (30, 130)
protruding from the bore surface (28, 128). Each locking wing having a
sloping locking surface (34, 134) and stopper (36, 136) with a stop surface
(40, 140). The screw member (18, 118) outwardly radially protruding
clamping wings (66, 166), each having a sloping clamping surface (70, 170)
and an associated side abutment surface (71", 175"). The screw member is
in threaded engagement with the tool shank, with the clamping wings and
locking wings aligned in pairs with the locking and clamping surfaces (34, 70;
134, 170) of each pair in abutment and with each stop surface (40, 140) is
in abutment with a given side abutment surface (71", 175").

Documents:

1653-KOLNP-2004-FORM-27-1.pdf

1653-KOLNP-2004-FORM-27.pdf

1653-kolnp-2004-granted-abstract.pdf

1653-kolnp-2004-granted-assignment.pdf

1653-kolnp-2004-granted-claims.pdf

1653-kolnp-2004-granted-correspondence.pdf

1653-kolnp-2004-granted-description (complete).pdf

1653-kolnp-2004-granted-drawings.pdf

1653-kolnp-2004-granted-examination report.pdf

1653-kolnp-2004-granted-form 1.pdf

1653-kolnp-2004-granted-form 13.pdf

1653-kolnp-2004-granted-form 18.pdf

1653-kolnp-2004-granted-form 2.pdf

1653-kolnp-2004-granted-form 3.pdf

1653-kolnp-2004-granted-form 5.pdf

1653-kolnp-2004-granted-form 6.pdf

1653-kolnp-2004-granted-gpa.pdf

1653-kolnp-2004-granted-reply to examination report.pdf

1653-kolnp-2004-granted-specification.pdf

1653-KOLNP-2004-OTHERS.pdf


Patent Number 234240
Indian Patent Application Number 1653/KOLNP/2004
PG Journal Number 20/2009
Publication Date 15-May-2009
Grant Date 12-May-2009
Date of Filing 04-Nov-2004
Name of Patentee ISCAR LTD.
Applicant Address P.O. BOX 11, 24959 TEFEN
Inventors:
# Inventor's Name Inventor's Address
1 HECHT, GIL 30/18 AHAD HA'AM STREET, 22443 NAHARIYA
PCT International Classification Number B23B 31/11
PCT International Application Number PCT/IL2003/00405
PCT International Filing date 2003-05-19
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 150013 2002-06-04 Israel