GB1604667A

GB1604667A - Cutter tool holder assemblies

Info

Publication number: GB1604667A
Application number: GB9074/77A
Authority: GB
Original assignee: WIMET Ltd
Current assignee: WIMET Ltd
Priority date: 1977-03-03
Filing date: 1977-03-03
Publication date: 1981-12-16
Also published as: ZA781000B

Description

(54) IMPROVEMENTS IN OR RELATING TO CUTTER TOOL HOLDER ASSEMBLIES (71) We, WIMET LIMITED, a British Com- pany of Torrington Avenue, Coventry CV4 9AD England, 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:: In our parent patent specification 1 344 010 we described and claimed a cutter tool holder assembly comprising a shank to be mounted in a milling cutter for rock drilling and a tool holder mounted in said shank by means of a tongue and groove connection, the mouth of the groove being narrowed by respective projections from opposite sides of the groove, each said projection having opposed contact surfaces which converge together in the direction from which the tongue part is mounted and engage corresponding contact surfaces on the tongue part.The tongue and groove connection was said to preferably be a T-slot connection, one part of the connection having a T-shaped tongue projecting from its body and fitting into the groove in the other part of the connection, the cross of the T providing one pair of the contact surfaces of the holder and the body providing respectively opposed contact surfaces of the holder.

In patent specification No. 1 388 503 the same principle is applied to cutter tool holders mounted directly in the milling cutter head of a rock drilling machine.

With the above mentioned T-slot connection there is obtained a connection of sufficient strength but considerable costs are connected therewith to an extent that makes it desirable to find less expensive alternatives which still provide a connection of adequate stability and strength.

With a view to overcoming these difficulties we have, according to the present invention, eliminated use of a specifically T-form tongue and groove connection comprising a groove whose mouth is narrowed by two separate projections from opposite sides of the groove.

According to the present invention we provide an assembly of a cutter head and cutter tool holder for a rock or the like drilling machine, the cutter tool holder being mounted in the head by means of a tongue-and-groove connection, the groove being narrowed by a projection from one only of its sides and the tongued member of the connection having opposed contact means respectively engageable with corresponding contact means of the grooved member of the connection whereby the two members can be wedgedly locked together, one of the corresponding contact means being constituted by that portion of the projection which is nearer the base of the groove.

The invention also resides in a cutter tool holder for use in creating an assembly as defined in the preceding paragraph.

Three embodiments of this invention will now be described in further detail, by way of example only, with reference to the accompanying drawings. In the drawings: Figure 1 is a view taken from the front side of a cutter tool holder; Figure 2 is a side view of the holder in Figure 1; Figure 3 is a top view of a part of the cutter head; Figure 4 is a view taken on the line IV-IV of Figure 3 showing part of a first assembly according to the invention with the cutter head in section but showing the whole cutter tool holder in side view (except where obscured by the cutter head); Figure 5 is a section on the line V-V of Figure 4; Figure 6 is a view similar to that of Figure 4, but showing part of a second assembly according to the invention; Figure 7 is a section on the line Vil-Vil of Figure 6;; Figure 8 is a section through part of a cutter head of a third embodiment of the invention showing a cutter tool holder in position; Figure 9 is a front view of the holder; and Figure 10 is a section on the line X-X of Figure 8.

In the accompanying drawings Figures 1 and 2 show a tool holder 10 having a cutting insert 11 of a wear-resistant material, usually sintered carbide. The holder 10 has a downwardly projecting portion 12 which in turn has a lateral projection 13. The holder comprises planar sur faces 14 and 15 which converge, as best seen in Figures 2 and 4.

The holder 10 is carried in a shaft member or directly in a cutter head 16, as shown in Figures 3 to 5, by means of a tongue-and-groove connection. The cutter head 16 is to be rotated about its axis so that the cutters move in the direction of arrow A in Figures 4 and 6 and at the same time the cutter head is given an orbital movement at right angles to its axis of ro tation. In the embodiment illustrated in Figures 1 to 5, the tongue-and-groove connection has the form of an Gslot connection which comprises a groove 17 in said shaft or cutter head, the mouth of which groove is narrowed by a single projection 21 from one side so as to form an Gslot as can be seen in Figure 5.This projection 21 does not run the full length of the groove which therefore has an un-narrowed opening 22 at one end through which the L shaped tongue can be inserted or removed. The projection 21 has two mutually opposite faces 20 and 19 which converge towards the opening 22. Surfaces 14 and 15 on the cutter head converge at the same angle When the projecting portion 12 of the cutter head is pushed into the opening 22 and along the L-slot, the cutter head becomes rigidly wedged with the surface 15 of the lateral projection 13 abutting the surface 19 of the projection 21, with the surface 14 of the holder 10 abutting the surface 20 of the projec tion 21, and with the holder 10 held clear of the base 18 ofthe groove 17.

The wedging angle between the opposed contact surfaces 19 and 20 preferably should be 10 to 15 so that the cutter tool holders become firmly fastened to the cutter head. If the said angle should exceed such values the connection will not be self-locking.

Figures 6 and 7 show an alternate embodiment of the invention in which the projection 21 comprises a cylindrical pin secured in the groove 17 by means of a weld 29, and the projecting portion 12 of the holder 10 has a groove 23 in which the projection 21 fits slidingly. The converging contact means on the cutter head 16 are provided by the pin 21 which projects into the groove 17 and the surface of the cutter head adjacent to the groove, and the converging contact means on the tool holder 10 by the groove 23 in the projecting portion 12 and the surface 14. The end of the face of the portion 12 to the left of the line 30 (as seen in Figure 6) is cut back level with the rear of the groove 23 to enable the tool holder 10 to be removed from the groove 17 on being moved to the right and then upwardly.

Figure 6 also shows locking means (shown generally at 27) which prevents disengagement of head 16 and holder 10 when the cutters are moved in the direction opposite to that indicated by arrow A, which "reverse rotation" may sometimes be required in coal-mining. The locking means 27 comprises a locking pin 25 and resilient material 25 which urges the pin 24 to extend into the mouth 22 of the groove, so that disengagement of head 16 and holder 10 is prevented by the engagement of the pin 24 with wall 28 of the groove. The locking pin 24 is further provided with a resilient tubular pin 26 26 for keeping the locking pin 24 in a fixed position. For removal of the holder from the head, pin 24 is urged upwards from the groove by a tool engaging pin 26.

The embodiment shown in Figures 8 to 10 differs from that of Figures 6 and 7 in that the downwardly projecting portion 12 of the holder 10 is at right angles or substantially at right angles to the under surface 14 which is to form the upper contact means of the holder. This means that the groove 23 in the projecting portion 12 must be cut at an angle, as shown in the drawings, in order to form the wedging angle with the surface 14. The cylindrical pin 21 is mounted as before in a semi-circular recess at the side of the groove 17 in the cutter head 16, where it is welded at 29; it is of course angled in the same way as the groove 23 in the projec tingportion 12.

The locking pin 31 is generally J-shaped comprising a longer leg 32, a cross-piece 33 and a shorter leg 34. The two legs are located in bores 35 and 36 in the head 16, the leg 34 being fitted with an 0-ring 37 to prevent the passage of dirt. The cross-piece 33 lies in an open passage 39 in the head 16 which connects the two bores 35 and 36.

As seen in Figure 10, the shorter leg 34 extends inwardly into the groove 17 in which the projecting portion 12 of the holder 10 lies and prevents its removal when in the position shown.

The bore 35 passes through the cutter head 16 and, at the end remote from the passage 39 opens out into a cylindrical chamber 40 of greater diameter in which is located a rubber pad41. A collar 42 fixed adjacent the outer end of the leg 32 of the locking means 31 bears against the rubber pad 41 which biasses the locking means into position shown.

It can readily be seen that manual pressure on the end of the locking means 31 adjacent the collar 42 can push this against the bias of the rubber pad and the means will move into a position where the shorter leg 34 lies clear of the groove 17, thus allowing the holder 10 to be removed from the cutter head.

Obviously the locking means disclosed in Figures 6 and 7, or that disclosed in Figures 8 and 10, can be used with any of the embodiments of the invention.

In another aspect of the present invention, a new locking means has been devised to prevent disengagement of a removable cutter tool holder from a cutter head or like machine part to which it is attached. This locking means comprises a J-shaped pin located in the machine part and movable between a first position in which the shorter leg of the pin blocks the removal of a cutter tool holder mounted in the machine part and a second position in which this leg ceases to block such removal, the pin being resiliently biassed towards the first position but readily movable against this bias into the second position to allow the tool holder to be removed.

In our pending cognate patent application Nos. 80.10911/2 (Serial No. 1604668) divided out from the present applications we claim a coal cutter tool holder assembly comprising a cutter tool holder and a carrier for said holder on which said holder is mounted by means of a tongue and groove connection comprising opposed divergent contact surfaces of the tongued member of the connection that are respectively engageable with co-acting opposed contact surfaces on the grooved member of the connection the contact surfaces being arranged so that the two members can be wedgedly connected together by their engagement whilst the end of the tongue is still short of the end of the groove.

WHAT WE CLAIM IS: 1. An assembly of a cutter head and cutter tool holder for a rock or the like drilling machine, the cutter tool holder being mounted in the head by means of a tongue-and-groove connection, the groove being narrowed by a projection from one only of its sides and the tongued member of the connection having opposed contact means respectively engageable with corresponing contact means of the grooved member of the connection whereby the two members can be wedgedly locked together, one of the corresponding contact means being constituted by that portion of the projection which is nearer the base of the groove.

2. An assembly according to Claim 1, wherein said opposed contact means converge at substantially the same angle as said corresponding contact means.

3. An assembly according to either of the preceding claims in which the groove has a closed base and the tongue is supported clear of the base.

4. An assembly according to any one of the preceding claims in which said tongued member is the cutter tool holder and said grooved member is the cutter head.

5. An assembly according to any one of the preceding claims wherein the opposed contact means of the tongued member are planar and convergent, and the corresponding contact means of the grooved member are also planar and convergent.

6. An assembly according to any one of the preceding claims in which the other of said corresponding contact means is constituted by that portion of the projection remote from the base of the groove.

7. An assembly according to Claim 6 in which that portion of the projection remote from the base is contiguous with the mouth of the groove.

8. An assembly according to any one of Claims 1 to 4 wherein the projection is constituted by a pin set in one wall of the groove and arranged generally longitudinally of the groove.

9. An assembly according to Claim 8 wherein the tongued member has a groove into which the said pin can fit, part of the groove thus forming one of the contact means on the tongued member.

10. An assembly according to Claim 9 in combination with Claim 4 wherein the groove in the tongued member forming one of the contact means is formed in a projecting portion of the cutter tool holder which is substantially at right angles to the other contact means on the cutter tool holder.

11. An assembly according to any one of the preceding claims and comprising a locking means wherein the tongued member bears a pin and associated urging means such that when the tool holder is wedgedly supported in the cutter head, said urging means causes said pin to project into said groove whereby to prevent unwedging movement of the holder.

12. An assembly according to any one of Claims 1 to 10 and comprising a locking means in the form of a J-shaped pin located in the grooved member and movable between a first position in which the shorter leg of the pin extends into the groove and blocks the unwedging movement of the tool holder and a second position in which this leg ceases to block such movement, the pin being resiliently biassed towards the first position but readily movable against this bias into the second position to allow the tool holder to be removed.

13. A cutter tool holder for connection to a cutter head of a rock or the like drilling machine, contact face outside the groove inclined to the projection from one only of its sides to provide a contact face within the groove and an opposed contact face outside the grovoe inclinde to the first contact face, said cutter tool holder having a tongue constructed to be inserted in the groove and opposed contact faces for wedging against the corresponding contact faces of the cutter head when the said tongue is moved within the groove.

14. An assembly of a cutter head and cutter tool holder as claimed in Claim 1, constructed and arranged for use substantially as shown in Figures 1 to 5 and Figures 6 and 7 of the acocompanying drawings and described herein with reference thereto.

15. An assembly of a cutter head and cutter tool holder as claimed in Claim 1, constructed and arranged for use substantially as shown in Figures 8 to 10 of the accompanying drawings and described herein with reference thereto.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. removal of a cutter tool holder mounted in the machine part and a second position in which this leg ceases to block such removal, the pin being resiliently biassed towards the first position but readily movable against this bias into the second position to allow the tool holder to be removed. In our pending cognate patent application Nos. 80.10911/2 (Serial No. 1604668) divided out from the present applications we claim a coal cutter tool holder assembly comprising a cutter tool holder and a carrier for said holder on which said holder is mounted by means of a tongue and groove connection comprising opposed divergent contact surfaces of the tongued member of the connection that are respectively engageable with co-acting opposed contact surfaces on the grooved member of the connection the contact surfaces being arranged so that the two members can be wedgedly connected together by their engagement whilst the end of the tongue is still short of the end of the groove. WHAT WE CLAIM IS:

1. An assembly of a cutter head and cutter tool holder for a rock or the like drilling machine, the cutter tool holder being mounted in the head by means of a tongue-and-groove connection, the groove being narrowed by a projection from one only of its sides and the tongued member of the connection having opposed contact means respectively engageable with corresponing contact means of the grooved member of the connection whereby the two members can be wedgedly locked together, one of the corresponding contact means being constituted by that portion of the projection which is nearer the base of the groove.