Blade positioning structure of disposable milling cutter

Abstract

A blade positioning structure of a disposable milling cutter includes a cutter body and a disposable blade. The cutter body is peripherally provided with a blade seat. By passing a screw through the disposable blade and the blade seat, the disposable blade is locked to the blade seat. The blade seat has a blade seat surface and a sidewall; the blade seat surface has a groove; the disposable blade has a bottom surface provided with a projection corresponding in shape to the groove; and when the disposable blade is locked to the blade seat, the blade seat surface and the groove of the latter lie respectively and tightly against the bottom surface and the projection of the former.

Claims

1. A blade positioning structure of a disposable milling cutter, the disposable milling cutter comprising: a cutter body, the cutter body having a pair of opposing planar sides and an outer periphery provided with a blade seat, the blade seat extending transversely through the cutter body and having a threaded hole, the threaded hole being inclined at a first angle relative to the pair of opposing planar sides; and a disposable blade, the disposable blade being positioned in the blade seat and penetrated by a screw hole, the screw hole being inclined at a second angle equal to the first angle of the threaded hole to align therewith, and the disposable blade being locked to the blade seat by passing a screw through the screw hole and the threaded hole, the screw being inclined relative to the pair of opposing planar sides of the cutter body thereby; wherein the blade seat has a blade seat surface and a sidewall, the blade seat surface being provided with at least one groove; wherein the disposable blade has a bottom surface provided with at least one bottom projection and a top surface provided with at least one top projection, each of the bottom projection and the top projection corresponding in shape to the groove in the blade seat surface, said groove in the blade seat surface matingly engageable with either the disposable blade bottom projection or the disposable blade top projection interchangeably; and wherein the blade seat surface and the groove of the blade seat lie respectively and tightly against a respective one of the top surface or the bottom surface and the corresponding top or bottom projection of the disposable blade when the disposable blade is locked to the blade seat.

2. The blade positioning structure of claim 1, wherein the number of the at least one groove in the blade seat surface, the number of the bottom projection and the number of the top projection of the disposable blade are set according to a width of the milling cutter.

3. The blade positioning structure of claim 1, wherein the sidewall of the blade seat is provided with an aperture, the aperture has two lateral walls each provided with a chamfer, the two chamfers jointly define a V-shaped groove, and the disposable blade has a V-shaped end corresponding in shape to and receivable in the V-shaped groove.

4. The blade positioning structure of claim 1, wherein the bottom projection and the top projection of the disposable blade are curved projections, and the groove in the blade seat surface is a curved groove.

5. The blade positioning structure of claim 1, wherein the bottom projection and the top projection of the disposable blade are curved projections, and the groove in the blade seat surface is a frustum-shaped hole.

6. The blade positioning structure of claim 4, wherein the curved groove in the blade seat surface is provided at a blade seat of a lathe cut-off tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention as well as a preferred mode of use and the advantages thereof will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which:

(2) FIG. 1 is a perspective view of an embodiment of the present invention;

(3) FIG. 2 is a partial side view of an embodiment of the present invention;

(4) FIG. 3 is a schematic assembled view of a curved projection and a curved groove in an embodiment of the present invention;

(5) FIG. 4 is a partial assembled front view of a disposable blade and a blade seat in an embodiment of the present invention;

(6) FIG. 5 is a perspective view of a disposable T-slot cutter employing an embodiment of the present invention;

(7) FIG. 6 is a perspective view of a disposable side milling cutter employing an embodiment of the present invention;

(8) FIG. 7 is a perspective view of another disposable T-slot cutter employing an embodiment of the present invention;

(9) FIG. 8 is a perspective view of another disposable side milling cutter employing an embodiment of the present invention;

(10) FIG. 9 is a perspective view of a disposable lathe cut-off tool employing an embodiment of the present invention;

(11) FIG. 10 is a partial side view of another embodiment of the present invention;

(12) FIG. 11 schematically shows a conventional T-slot cutter with soldered blades;

(13) FIG. 12 schematically shows a conventional side milling cutter with soldered blades;

(14) FIG. 13 schematically shows a conventional disposable T-slot cutter;

(15) FIG. 14 schematically shows a conventional disposable side milling cutter; and

(16) FIG. 15 schematically shows a conventional disposable side milling cutter whose blade seats have one sidewall only.

DETAILED DESCRIPTION OF THE INVENTION

(17) FIG. 1 and FIG. 2 illustrate the blade positioning structure of a disposable milling cutter according to an embodiment of the present invention, wherein the disposable milling cutter includes a cutter body 10 and a plurality of disposable blades 20.

(18) The cutter body 10 has an outer periphery provided with a plurality of blade seats 11. Each blade seat 11 extends transversely through (i.e., through the thickness, or width, of) the cutter body 10 and has a blade seat surface 111 and a sidewall 112.

(19) Each blade seat surface 111 is provided with a curved groove 113 and a threaded hole 114.

(20) The disposable blades 20 are provided at the blade seats 11 of the cutter body 10 respectively. For the sake of simplicity, the blade positioning structure of the present invention is detailed hereinafter with reference to only one disposable blade 20 and one blade seat 11 by way of example.

(21) In this embodiment, the disposable blade 20 has a bottom surface 222 provided with a curved projection 23, wherein the shape of the curved projection 23 corresponds to that of the curved groove 113 of the blade seat 11. Also, the disposable blade 20 is penetrated by a screw hole 21, which is aligned with the threaded hole 114 in the blade seat surface 111 of the blade seat 11 so that a screw 30 can pass sequentially through the screw hole 21 and the threaded hole 114 and thereby lock the disposable blade 20 to the cutter body 10. Preferably, the screw hole 21 of the disposable blade 20 includes a countersunk hole 211 at each of its two ends.

(22) As previously mentioned, the curved projection 23 of the disposable blade 20 corresponds in shape to the curved groove 113 of the blade seat 11. Therefore, in the course in which the disposable blade 20 is mounted to the blade seat 11, the curved projection 23 on the bottom surface 222 of the disposable blade 20 is guided by and thus slides rapidly into the curved groove 113 of the blade seat 11; as a result, the positioning of the disposable blade 20 is completed promptly. The disposable blade 20 preferably has a top surface 221 provided with another curved projection 23 so that, when it is necessary to turn the disposable blade 20 over in order to use an unused cutting edge instead of the one that is already worn, the curved projection 23 on the top surface 221 will also be guided by and slide swiftly into the curved groove 113 of the blade seat 11 to help position the disposable blade 20 rapidly. Once the positioning process is completed, the disposable blade 20 is locked to the blade seat 11 with the screw 30 to press the curved projection 23 of the disposable blade 20 tightly against the curved groove 113 of the blade seat 11, and the bottom surface 222 (or top surface 221) of the disposable blade 20 tightly against the blade seat surface 111 of the blade seat 11.

(23) As shown in FIG. 2, the bottom surface 222 (or top surface 221) and the curved projection 23 of the disposable blade 20 are in contact with the blade seat surface 111 and the curved groove 113 of the blade seat 11 respectively. In consequence, a double-face contact exists between the disposable blade 20 and the blade seat 11 in the vertical direction (i.e., the Z-axis direction) and limits the degree of freedom of the disposable blade 20 in the vertical direction (i.e., the Z-axis direction).

(24) Moreover, referring to FIG. 3, as the contact surface between the curved projection 23 of the disposable blade 20 and the curved groove 113 of the blade seat 11 is a curved one, the contact force acting on which can be divided into a horizontal component and a vertical component, the degree of freedom of the disposable blade 20 is limited in the horizontal direction (i.e., the X-Y plane direction) as well as in the vertical direction (i.e., the Z-axis direction). In particular, when the disposable blade 20 is tightly locked to the blade seat 11 by the screw 30 (see FIG. 2), the degree of freedom of the disposable blade 20 is further limited in the horizontal direction (i.e., the X-Y plane direction), or more specifically in both X-axis and Y-axis directions, preventing the disposable blade 20 from moving or vibrating under cutting stress.

(25) Referring to FIG. 4, when the disposable blade 20 is subjected to a cutting stress F, the horizontal component F.sub.XY of the cutting stress F is borne by the sidewall 112 of the blade seat 11, and the vertical component F.sub.Z of the cutting stress F is borne by the blade seat surface 111 of the blade seat 11.

(26) Thus, once the disposable blade 20 is tightly locked to the blade seat 11, the degree of freedom of the disposable blade 20 is limited in all three axial directions, allowing cutting stress to be transmitted smoothly, and the stability of the cutter is enhanced as a result.

(27) FIG. 5 and FIG. 6 show an application example in which the blade positioning structure of the present invention is applied to a disposable T-slot cutter and a disposable side milling cutter. In this application example, the disposable blades 20 can be as wide as the blade seats 11 due to the fact that the blade seats 11 of the disposable T-slot cutter and of the side milling cutter do not require two sidewalls. The disposable blades 20 can be even wider to suit the widths of the grooves to be cut. Or the disposable blades 20 and the blade seats 11 can both be widened, as shown in FIG. 7, with each disposable blade 20 provided with an appropriate number of curved projections 23, and each blade seat 11, with the corresponding number of curved grooves 113 (in this application example, but without limitation, each disposable blade 20 is provided with two curved projections 23, and each blade seat 11 is provided with two curved grooves 113) in order to increase the maximum tolerable cutting stress, and hence the cutting power, of the disposable blades 20.

(28) Please refer to FIG. 8 for another application example, in which the blade positioning structure of the present invention is applied to a disposable V-groove cutter 40. The disposable V-groove cutter 40 has a plurality of blade seats 41 and a plurality of disposable blades 20. For the sake of simplicity, the following detailed description refers to only one blade seat 41 and one disposable blade 20 by way of example. The blade seat 41 has a curved groove 411, and the disposable blade 20 has a curved projection 23. The curved groove 411 corresponds in shape to the curved projection 23 so that the curved projection 23 can be guided by and therefore slides rapidly into the curved groove 411 to complete the positioning of the disposable blade 20 without delay. What is special about this application example is that the blade seat 41 of the disposable V-groove cutter 40 further has a V-shaped end and a sidewall 42 provided with an aperture 421. The aperture 421 has two lateral walls each provided with a chamfer 422, and the two chamfers 422 jointly define a V-shaped groove 423. On the other hand, the disposable blade 20 of the disposable V-groove cutter 40 has two V-shaped ends. As the two V-shaped ends of the disposable blade 20, the V-shaped end of the blade seat 41, and the V-shaped groove 423 in the sidewall 42 of the blade seat 41 correspond in shape to one another, the V-shaped groove 423 can receive either V-shaped end of the disposable blade 20 to thereby position the disposable blade 20. Once the disposable blade 20 is positioned at the blade seat 41 of the V-groove cutter 40, the disposable blade 20 can be securely locked to the blade seat 41 with a screw 30 as in the embodiment described above.

(29) FIG. 9 shows yet another application example, in which the blade positioning structure of the present invention is applied to a disposable lathe cut-off tool 70. Like the disposable side milling cutters and disposable T-slot cutters in the foregoing application examples, the disposable cut-off tool 70 has a blade seat 71 with only one sidewall 710. The blade seat 71 is provided with a curved groove 711 and a threaded hole 712 so that a disposable blade 20 can be locked to the blade seat 71 with a screw 30. In addition, due to the curved groove 711 of the blade seat 71, a double-face contact exists between the disposable blade 20 and the blade seat 71 in the vertical direction (i.e., the Z-axis direction) and limits the degree of freedom of the disposable blade 20 in the vertical direction (i.e., the Z-axis direction). As the contact surface between the curved projection 23 of the disposable blade 20 and the curved groove 711 of the blade seat 71 is a curved one, the degree of freedom of the disposable blade 20 is limited in the horizontal direction (i.e., the X-Y plane direction) as well as in the vertical direction (i.e., the Z-axis direction). In particular, when the disposable blade 20 is tightly locked to the blade seat 71 by the screw 30, the degree of freedom of the disposable blade 20 is further limited in the horizontal direction, or more specifically in both X-axis and Y-axis directions, to prevent the disposable blade 20 from moving or vibrating under cutting stress.

(30) FIG. 10 shows the blade positioning structure of a disposable milling cutter according to another embodiment of the present invention. In this embodiment, the disposable blade 100 has a top surface 121 and a bottom surface 122 each being provided with a frustum-shaped projection 123, and the blade seat 300 is provided with a frustum-shaped hole 313. Either of the frustum-shaped projections 123 can be received in the frustum-shaped hole 313 of the blade seat 300, and the disposable blade 100 is in position as soon as either frustum-shaped projection 123 is received in the frustum-shaped hole 313 of the blade seat 300. When the disposable blade 100 is subsequently tightly locked to the blade seat 300 with a screw 200, the degree of freedom of the disposable blade 100 is limited in all three axial directions.

(31) According to the above, the top surface and the bottom surface of the disposable blade of the present invention are each provided with a projection corresponding in structure to the groove of the blade seat. Therefore, the blade seat of the disposable milling cutter of the present invention requires only one sidewall, and there is no need for each two adjacent disposable blades to be arranged diagonally (i.e., in a staggered arrangement). As a result, the number of the effective cutting edges of the disposable milling cutter of the present invention is increased in comparison with that which the blade positioning structure of a conventional disposable milling cutter allow. For example, given the same number of blades, the disposable milling cutter of the present invention will have the same number of effective cutting edges as a milling cutter with soldered blades such that both cutting speed and feed speed are increased comparatively, allowing an effective increase in cutting efficiency and the realization of maximum economic benefit. Being the first of its kind in the cutter industry, the structural design disclosed herein is of great novelty and inventiveness.