GB1587692A

GB1587692A - Arrangement for mounting a cutter on a driven spindle

Info

Publication number: GB1587692A
Application number: GB1763378A
Authority: GB
Original assignee: Kennametal Inc
Current assignee: Kennametal Inc
Priority date: 1977-06-13
Filing date: 1978-05-04
Publication date: 1981-04-08
Also published as: DE7816188U1; DE2823609A1; CA1079505A

Description

(54) ARRANGEMENT FOR MOUNTING A CUTTER ON A DRIVEN SPINDLE (71) We, KENNAMETAL INC., a corporation of the Commonweath of Pennsylvania, United States of America, of One Lloyd Avenue, Latrobe, Pennsylvania 15650, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to mounting arrangements for mounting a cutter in a driven spindle e.g. for use in milling machine arbors.

Prior art arrangements for mounting milling cutters may be found in The Machinery's Handbook and other similar sources. These arrangements usually require the removal of several bolts and the like before removal and replacement of the cutter body can be achieved.

According to one aspect of the present invention, there is provided a mounting arrangement comprising; a milling cutter and a power driven spindle rigidly connected by an arbor and having cooperating elements of axial abutment means and cooperating elements of keying means between said spindle and said cutter, a bore having a shoulder formed in one of said spindle and said cutter, and radially movable clamp elements mounted in a recess formed on one end of said arbor, said clamp elements being movable radially outwardly so as to abuttingly engage said shoulder in said bore and urge said cooperating elements of abutment means into axial engagement, whereby the cutter, arbor and spindle are held together for rotation about a common axis.

According to a further aspect of the invention, there is provided a method of mounting a cutter on a power driven spindle for rotation on a common axis comprising the steps of interconnecting said spindle and said cutter with an arbor, abutting one side of said cutter to one end of said spindle, keying said cutter to said spindle and engaging a shouldered bore in one of said spindle and said cutter with radially movable clamp elements carried by said arbor so as to urge said cutter and said spindle into form abutment with one another.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings, in which: Figure 1 is a side view partly in section showing a milling cutter and spindle with a connecting arbor holding a clamping arrangement; Figure 2 is a transverse sectional view of the clamping arrangement of Figure 1; Figure 3 is a fragmentary plan sectional view showing a key arrangement.

Figure 4 is a fragmentary view showing a modification; and Figure 5 is a side view partly in section showing a different arbor arrangement.

Referring to the drawings in more detail, and with particular reference to Figures 1 to 4, there is shown a power driven spindle 10 having a central bore 12 terminating in an outwardly tapering portion 13. Tapering portion 13 is adapted for receiving a tapered arbor 14 which, at the end inside spindle 10, is threadedly engaged by a drawbar 16.

The other end of arbor 14 projects axially outwardly from the end of spindle 10 and is received in a central hole in cutter body 18 of a milling cutter. The outer end of arbor 14 has a cylindrical portion 20 thereon which is closely receivable inside central bore 22 in body 18.

Body 18 has an annular recess 24 formed therein which includes an inclined shoulder portion 26 engageable by clamp elements 28 in the form of balls located in respective, substantially radial bores 30 formed in the outer end of arbor 14. The arbor includes a threaded axial central recess 32 within which is threaded a clamp screw 34 that engages the axially movable actuator ball 36 mounted in the bore.

It will be evident that rightward movement of actuator ball 36 will force clamp balls 28 radially outwardly into engagement with shoulder 26 thereby to clamp cutter body 18 fixedly in place with the surface 38 of the cutter body firmly pressed against surface 40 on the end of the arbor.

Rotation of the body 18 on the central axis of arbor 14 and spindle 10, the body may be provided with a keyway 42 while a key 44 is mounted in a notch 46 provided therefor in the end of spindle 10 with the key block fixed in place by a screw 48.

The arrangement provides for a simple and extremely rapid manner of mounting cutter bodies on spindle 10 and of removing cutter bodies therefrom. No clamp bolts or the like are required and the illustrated arrangement will remain effective over a long period of time.

The shoulder 26 which is engaged by the clamp balls 28 may be provided by a hardened ring 50 mounted in body 18 as shown in Figure 4 and having a frustoconical engagement surface. Ring 50 can be fixed to body 18 in any suitable manner in order properly to transfer the clamping loads from clamp balls 28 to cutter body 18.

Figure 5 shows a modification in which a spindle 60 has a central bore 62 therein with a ring 64 having a frusto-conical engagement surface. The ring 64 is, advantageously of hardened steel, and is mounted in the outer end of the bore and clamped therein as by clamp screw 66. Ring 64 has an inclined shoulder 68 formed on the inner end and internally is of a size to receive and closely embrace an arbor 70 which has an axially outer end 72 fitted in a central bore 74 in a cutter body 76. A tubular clamp bolt 78 threads into the outer end 72 of arbor 70 and clamps the cutter body against shoulder 80 formed on arbor 70.

The body 76 may include a keyway 82 into which a key 84 fixed on spindle 60 extends to hold cutter body 76 against rotation on the spindle.

Arbor 70 has a central bore 86 which receives an actuator ball 88 and which central bore is intersected by radial bores 87 each having a clamp ball 90 therein engageable with shoulder 68 when actuator ball 88, of larger diameter than the clamp balls 90, is moved to the right. Movement of the actuator ball 88 is accomplished by a screw 92 mounted in a threaded bore 94 in arbor 70, the outer end of which screw 92 is accessible through the central bore 96 in clamp screw 78, which central bore may, to advantage, be configured to receive a drive wrench for rotation of clamp screw 78. Each clamp ball 90 is engaged by actuator ball 88 and shoulder 68 at respective abutment surfaces to which respective tangential planes can be drawn which converge towards shoulder 80 abutted by cutter body 76.

In each embodiment illustrated it will be apparent that when the radially movable clamp elements engage said shoulder the cooperating elements of abutment means between the cutter body and the spindle are urged into a firm abutting relationship. The other end of the arbor which is not carrying the clamp elements is fixedly secured to said spindle (Figure I) or said cutter (Figure 2).

The other end of said arbor may be secured by a tapered drawbar to the power driven spindle or by threadingly engaging an end cap member which holds the cutter body to the arbor.

WHAT WE CLAIM IS: 1. A mounting arrangement comprising; a milling cutter and a power driven spindle rigidly connected by a arbor and having cooperating elements of axial abutment means and cooperating elements of keying means between said spindle and said cutter, a bore having a shoulder formed in one of said spindle and said cutter, and radially movable clamp elements mounted in a recess formed on one end of said arbor, said clamp elements being movable radially outwardly so as to abuttingly engage said shoulder in said bore and urge said cooperating elements of abutment means into axial engagement, whereby the cutter, arbor and spindle are held together for rotation about a common axis.

2. The arrangement according to Claim 1 in which a central axial perforation is formed in one end of said arbor and communicates with radially outwardly extending bores having said clamp elements located therein, and an actuator element located and axially movable within said perforation.

3. The arrangement according to Claim 1 or 2 in which at least one of said clamp elements has two portions of abutment surfaces to which repective tangential planes can be drawn which converge toward said cooperating elements of axial abutment means.

4. The arrangement according to any one of Claims 1 to 3 in which said shoulder has a frusto-conical surface facing generally away from said cooperating elements of abutment means and said clamp elements have curved surfaces for engagement with said shoulder.

5. The arrangement according to Claim 4 when dependent on claim 3 wherein said clamp elements have spherical surfaces to engage said shoulder.

6. The arrangement according to Claim 5 wherein said clamp elements are respective metal balls having a first diameter and said actuator element is a metal ball having a diameter larger than said first diameter.

7. The arrangement according to Claim 1 in which said bore and shoulder are comprised of a bore and a tubular ring, having an outside diameter approximately equal to the diameter of said bore, interfitted in said bore and having said shoulder formed on one end thereof.

8. The arrangement according to Claim 1

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. on the end of the arbor. Rotation of the body 18 on the central axis of arbor 14 and spindle 10, the body may be provided with a keyway 42 while a key 44 is mounted in a notch 46 provided therefor in the end of spindle 10 with the key block fixed in place by a screw 48. The arrangement provides for a simple and extremely rapid manner of mounting cutter bodies on spindle 10 and of removing cutter bodies therefrom. No clamp bolts or the like are required and the illustrated arrangement will remain effective over a long period of time. The shoulder 26 which is engaged by the clamp balls 28 may be provided by a hardened ring 50 mounted in body 18 as shown in Figure 4 and having a frustoconical engagement surface. Ring 50 can be fixed to body 18 in any suitable manner in order properly to transfer the clamping loads from clamp balls 28 to cutter body 18. Figure 5 shows a modification in which a spindle 60 has a central bore 62 therein with a ring 64 having a frusto-conical engagement surface. The ring 64 is, advantageously of hardened steel, and is mounted in the outer end of the bore and clamped therein as by clamp screw 66. Ring 64 has an inclined shoulder 68 formed on the inner end and internally is of a size to receive and closely embrace an arbor 70 which has an axially outer end 72 fitted in a central bore 74 in a cutter body 76. A tubular clamp bolt 78 threads into the outer end 72 of arbor 70 and clamps the cutter body against shoulder 80 formed on arbor 70. The body 76 may include a keyway 82 into which a key 84 fixed on spindle 60 extends to hold cutter body 76 against rotation on the spindle. Arbor 70 has a central bore 86 which receives an actuator ball 88 and which central bore is intersected by radial bores 87 each having a clamp ball 90 therein engageable with shoulder 68 when actuator ball 88, of larger diameter than the clamp balls 90, is moved to the right. Movement of the actuator ball 88 is accomplished by a screw 92 mounted in a threaded bore 94 in arbor 70, the outer end of which screw 92 is accessible through the central bore 96 in clamp screw 78, which central bore may, to advantage, be configured to receive a drive wrench for rotation of clamp screw 78. Each clamp ball 90 is engaged by actuator ball 88 and shoulder 68 at respective abutment surfaces to which respective tangential planes can be drawn which converge towards shoulder 80 abutted by cutter body 76. In each embodiment illustrated it will be apparent that when the radially movable clamp elements engage said shoulder the cooperating elements of abutment means between the cutter body and the spindle are urged into a firm abutting relationship. The other end of the arbor which is not carrying the clamp elements is fixedly secured to said spindle (Figure I) or said cutter (Figure 2). The other end of said arbor may be secured by a tapered drawbar to the power driven spindle or by threadingly engaging an end cap member which holds the cutter body to the arbor. WHAT WE CLAIM IS:

1. A mounting arrangement comprising; a milling cutter and a power driven spindle rigidly connected by a arbor and having cooperating elements of axial abutment means and cooperating elements of keying means between said spindle and said cutter, a bore having a shoulder formed in one of said spindle and said cutter, and radially movable clamp elements mounted in a recess formed on one end of said arbor, said clamp elements being movable radially outwardly so as to abuttingly engage said shoulder in said bore and urge said cooperating elements of abutment means into axial engagement, whereby the cutter, arbor and spindle are held together for rotation about a common axis.

8. The arrangement according to Claim 1

which further comprises said bore and shoulder formed in said cutter and said arbor comprising a drawbar and tapering inwardly to an end opposite said one end of said arbor.

9. The arrangement according to Claim 1 which further comprises said shouldered bore formed in said spindle and the other end of said arbor having an end cap threadingly engaged therewith, said end cap clampingly engaging said cutter to said arbor.

10. A method of mounting a cutter on a power driven spindle for rotation on a common axis comprising the steps of interconnecting said spindle and said cutter with an arbor, abutting one side of said cutter to one end of said spindle, keying said cutter to said spindle, and engaging a shouldered bore in one of said spindle and said cutter with radially movable clamp elements carried by said arbor so as to urge said cutter and said spindle into firm abutment with one another.

11. A mounting arrangement for mounting a milling cutter substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3, or Figures 1 to 3 as modified by Figure 4, or Figure 5, of the drawings.

12. A method of mounting a cutter on a power-driven spindle substantially as hereinbefore described with reference to the drawings.