Patent Application
20150183029
The present invention relates to a tool holder assembly for removably securing a plurality of cutting inserts and a single multi-insert clamp therefor, for use in metal cutting processes in general, and for parting and cut-off operations in particular.
Within the field of tool holder assemblies for removably securing a plurality cutting inserts, devices are known having one or several insert receiving pockets, and devices having one insert receiving pocket are known having one or several clamping members.
U.S. Pat. No. 3,829,943 discloses a threading tool having a plurality of closely spaced cutting inserts to be held in a recess, a clamping arrangement for exerting individual pressure on each of said inserts comprising a set of digital clamps comprising a first member having at least one projecting finger, a second member having a plurality of projecting fingers, said members being in overlying orientation with said fingers in interdigital relation extending in one direction and defining a top clamp member and a bottom clamp member.
U.S. Pat. No. 6,612,207 discloses a turning assembly for turning a workpiece includes a holder and plurality of turning bits mounted next to one another in a parallel relationship for simultaneously engaging the workpiece. The turning bits are mounted in respective holding elements which are individually adjustably mounted in the holder. Spacers can be provided to space the turning bits apart. Safety devices are provided, each including an elastic element for frictionally retaining a respective turning bit and/or spacer within the holder to enable the holder to be manipulated without the turning bits and/or spacers falling out.
US 2011/0293382 A1 discloses a multi-grooving tool holder for holding cutting members seated in a side-by-side formation in a clamping portion of the holder. The clamping portion includes an upper clamp and a lower clamp and an elastic member is located in one of the upper and lower clamps. When cutting members are assembled in the clamping portion, the elastic member engages the cutting members and aligns each cutting member independently, by applying a force, and consequently a moment on the cutting members.
In accordance with the present invention, there is provided a multi-insert tool clamp for removably securing a plurality of cutting inserts in a tool holder body, the clamp comprising a tool holder connecting portion and an insert clamping portion spaced apart therefrom,
the insert clamping portion including a clamping protrusion and a plurality of clamping fingers,
wherein:
the clamping protrusion laterally extends along a clamping axis transverse to the at least one slot plane, and the at least one slot plane intersects the clamping protrusion.
Also in accordance with the present invention, there is provided a tool holder assembly for removably securing a plurality of cutting inserts, comprising a tool holder body with a single insert receiving pocket formed in a front end portion thereof, and the aforementioned clamp connected to the tool holder body.
Further in accordance with the present invention, there is provided a cutting tool comprising the aforementioned tool holder assembly, and a plurality of cutting inserts removably secured in the single insert receiving pocket.
For a better understanding, the invention will now be described, by way of example only, with reference to the accompanying drawings in which chain-dash lines represent cut-off boundaries for partial views of a member and in which:
Attention is first drawn to
According to the present invention, as shown in
In some embodiments of the present invention, the clamp 28 may have unitary one-piece construction.
As shown in
In other embodiments of the present invention (not shown), the connecting portion 30 may be integrally attached to the tool holder body 22.
As shown in
It should be appreciated that throughout the description and claims, use of the term “rearward” refers to a relative position in
According to the present invention, the insert clamping portion 32 includes a clamping protrusion 36 and a plurality of clamping fingers 38.
In some embodiments of the present invention, the plurality of clamping fingers 38 may be identical to each other.
Also, in some embodiments of the present invention, the clamping protrusion 36 may be located between the connecting portion 30 and the plurality of clamping fingers 38.
According to some embodiments of the present invention, as shown in
Also, according to some embodiments of the present invention, as shown in
It should be appreciated that throughout the description and claims of the present invention, the term “bisects” is used to describe clamping slots 42 divided into two equal or nearly equal parts.
In some embodiments of the present invention, each of the at least one clamping slot 42 may exhibit mirror symmetry about its associated slot plane P1.
Also, in some embodiments of the present invention, the clamping passage 40 may be in direct communication with the at least one clamping slot 42.
As shown in
In some embodiments of the present invention, as shown in
Each of the plurality of clamping fingers 38 having substantially constant lateral finger widths Wf is beneficial with respect to the manufacturing efficiency of the clamp 28.
The sum of the lateral finger widths Wf being greater than the sum of the slot widths Ws advantageously maximizes the number of clamping fingers 38 which can be provided within the clamping portion 32.
It should be appreciated that throughout the description and claims of the present invention, the term “substantially constant” is used to describe lateral finger and slot widths Wf, Ws which are constant with the possible exception of base end portions 44 of the clamping fingers 38, where stress-relief recesses 47 may be located.
In some embodiments of the present invention, each of the plurality of clamping fingers 38 may be elongated in a top to bottom direction of the clamp 28 parallel to one of the at least one slot plane P1 and transverse to the longitudinal axis L.
As shown in
Also, as shown in
In some embodiments of the present invention, as shown in
It should be appreciated that throughout the description and claims of the present invention, the term “substantially planar” is used to describe a support wall 48 having at least several coplanar sub-walls (not shown), as well as a single planar support wall 48.
As shown in
In some embodiments of the present invention, the clamping passage 40 may be elongated in the top to bottom direction of the clamp 28.
As shown in
In some embodiments of the present invention, by virtue of being elongated, each of the plurality of clamping fingers 38 may be independently resilient, having a resilience axis of rotation R1 transverse to one of the at least one slot plane P1.
It should be appreciated that throughout the description and claims of the present invention, the term “independently resilient” is used to describe a characteristic of the plurality of clamping fingers 38, where a resilient force exerted by one of the plurality of clamping fingers 38 is independent of a resilient force exerted by another of the plurality of clamping fingers 38.
Also, in some embodiments of the present invention, in contrast to the plurality of clamping fingers 38, which may be independently resilient, the clamping protrusion 36 may be rigid, and not have a resilience axis of rotation.
As shown in
In some embodiments of the present invention, each resilience axis of rotation R1 may be perpendicular to one of the at least one slot plane P1.
Also, in some embodiments of the present invention, the plurality of resilience axes of rotation R1 may be coaxial.
Further, in some embodiments of the present invention, as shown in
As shown in
Also, as shown in
In some embodiments of the present invention, the fastening member 34 may be a fastening screw and the fastening bore 54 may be a through bore, and the fastening member 34 may extend through the fastening bore 54 and threadingly engage a threaded holder bore 62 in the tool holder body 22.
Also, in some embodiments of the present invention, the connecting portion 30 may include a male or female type mounting member 64 extending along a mounting axis A3 transverse to the at least one slot plane P1.
As shown in
As shown in
Also, in some embodiments of the present invention, the tool holder body 22 may have a female or male type receiving member 66 adjacent the insert receiving pocket 24, and the male or female type mounting member 64 may slidably engage with the female or male type receiving member 66 along the mounting axis A3.
As shown in
According to the present invention, the clamping protrusion 36 laterally extends along a clamping axis A4 transverse to the at least one slot plane P1, and the at least one slot plane P1 intersects the clamping protrusion 36.
As shown in
In some embodiments of the present invention, the clamping protrusion 36 may have a uniform cross-section along the clamping axis A4.
Also, in some embodiments of the present invention, the clamping protrusion 36 may have a convex primary clamping surface 72 containing a first imaginary straight contact line L1 along which the primary clamping surface 72 may simultaneously contact a plurality of cutting inserts, each of the plurality of clamping fingers 38 may have a convex secondary clamping surface 74 containing a second imaginary straight contact line L2 along which the secondary clamping surface 74 may contact a single cutting insert, and the first and second imaginary straight contact lines L1, L2 may be parallel to the clamping axis A4.
Further, in some embodiments of the present invention, the plurality of second imaginary straight contact lines L2 may be collinear.
It should be appreciated that throughout the description and claims of the present invention, the plurality of second imaginary straight contact lines L2 may be collinear, within manufacturing tolerances, when the plurality of clamping fingers 38 are in a non-operative state.
As shown in
As shown in
In some embodiments of the present invention, the third and fourth imaginary straight lines L3, L4 may be perpendicular to their associated first and second imaginary straight contact lines L1, L2, respectively.
Also, in some embodiments of the present invention, the plurality of clamping fingers 38 may be separated by a plurality of clamping slots 42.
As shown in
The plurality of slot planes P1 being parallel is beneficial with respect to the manufacturing efficiency of the clamp 28.
Thus, as shown in
Attention is now drawn to
In some embodiments of the present invention, the total number of cutting inserts 78 may be equal to the total number of clamping fingers 38.
Also, in some embodiments of the present invention, the clamping protrusion 36 may make simultaneous clamping contact with each of the plurality of cutting inserts 78, and each of the plurality of clamping fingers 38 may make clamping contact with only one of the plurality of cutting inserts 78.
It should be appreciated that in some embodiments of the present invention, the clamping portion 32 may also include a non-clamping finger 80, which does not make clamping contact with any of the plurality of cutting inserts 78. The non-clamping finger 80 may be located at a lateral end 82 of the clamping portion 32, to protect its adjacent clamping finger 38 from cutting chip abrasions and wearing associated with metal machining operations.
In some embodiments of the present invention, the plurality of cutting inserts 78 may be identical to each other.
Also, in some embodiments of the present invention, each of the plurality of cutting inserts 78 may have two opposing end surfaces 84 and a peripheral side surface 86 extending therebetween, and at least one cutting edge 88 extending between the two opposing end surfaces 84.
As shown in
In some embodiments of the present invention, each second contact zone Z2 may span the width of its associated peripheral side surface 86.
Also, in some embodiments of the present invention, the first contact zones Z1 coincide with the first imaginary straight contact line L1 on the primary clamping surface 72, and the second contact zones Z2 coincide with their associated second imaginary straight contact lines L2 on the secondary clamping surfaces 74.
As shown in
In some embodiments of the present invention, the fifth and sixth imaginary straight lines L5, L6 may be collinear with the third and fourth imaginary straight lines L3, L4, respectively.
It should be appreciated that throughout the description and claims of the present invention, the term “external” is used to describe the contact angle α1 formed between the fifth and sixth imaginary straight lines L5, L6, when measured at their intersection external to the associated cutting insert 78.
In some embodiments of the present invention, the plurality of cutting inserts 78 may be removably secured in the insert receiving pocket 24 by means of the clamp 28 and the fastening member 34 operatively connected thereto. The clamping gaps G between the distal end portion 46 of each clamping finger 38 and the clamping protrusion 36 may decrease in response to the fastening member 34 being tightened and increase in response to the fastening member 34 being untightened.
The clamping gaps G may decrease during tightening of the fastening member 34, due to each clamping finger 38 being resiliently deflected along the peripheral side surface 86 of its associated cutting insert 78 towards the clamping protrusion 36.
In some embodiments of the present invention, the tightening of the fastening member 34 may be completed when the at least one stopper surface 52 of the connecting portion 30 bears against the at least one shoulder surface 56 of the tool holder body 22.
The clamping gaps G may increase during untightening of the fastening member 34 until the clamping portion 32 no longer makes clamping contact with the peripheral side surfaces 86 of the plurality of cutting inserts 78.
In some embodiments of the present invention, one of the two end surfaces 84 of one of the plurality of cutting inserts 78 may be in contact with the substantially planar support wall 48 of the insert receiving pocket 24.
Also, in some embodiments of the present invention, at least one of the two end surfaces 84 of each of the plurality of cutting inserts 78 may be in contact with one of the two end surfaces 84 of another cutting insert 78.
Further, in some embodiments of the present invention, the plurality of cutting inserts 78 may be laterally locked in a ‘side-by side’ arrangement against the support wall 48 by means of a locking screw 90 and a locking plate 92. The locking screw 90 may extend through bores associated with the locking plate 92 and the plurality of cutting inserts 78, respectively, and threadingly engage a threaded wall bore 94 in the support wall 48.
As shown in
In some embodiments of the present invention, the abutment ridge 50, which extends along the pivot axis A1 transverse to the support wall 48, may make abutting contact with each peripheral side surface 86.
As shown in
In some embodiments of the present invention, as shown in
The application of clamping forces F1, independently, to each second contact zone Z2, ensures that each cutting insert 78 suitably pivots about the pivot axis A1, until the clamping protrusion 36 makes clamping contact with each first contact zone Z1, and each cutting insert 78 reaches its operative orientation in the insert receiving pocket 24.
The application of independent clamping forces F1 advantageously accounts for and counteracts the manufacturing tolerances typically associated with the plurality of cutting inserts 78 to enable accurate and repeatable orientation of each cutting insert 78 within the insert receiving pocket 24.
During machining operations, the plurality of cutting inserts 78 are maintained in their operative orientations in the insert receiving pocket 24, due to cutting forces F2 acting on the operative cutting edges 88 in the second direction D2 about the pivot axis A1.
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.
