GB2039309A - Mineral - mining cutter assembly - Google Patents

Abstract

A cutting means assembly for a mineral cutting machine comprises a cutter pick 3 having a parallel-sided shank 3' by means of which the pick 3 is removably mounted in a correspondingly shaped aperture 2 of a cutter pick holder 1. The cutter pick 3 has a longitudinal axis x-x and a bore 5 is provided in the pick shank 3' transversely to the longitudinal axis. The holder 1 has two co-axial bores 4, one at each end of the bore 5, which bores 4 are substantially in axial alignment with the bore 5. An elongate member 6 of spring wire for axially retaining the cutter pick 3 in the holder 1, is located centrally in the bore 5 of the pick shank 3' and supported at the end portions in the bores 4 of the holder 1. The retaining member 6 is hook-shaped and comprises a shorter securing arm 8 and a longer locking or latching arm 7 which engages through the cutter pick shank 3' and has two humps 9. The retaining member 6 is located in the bores 4, 5 under prestressing. <IMAGE>

Description

SPECIFICATION Cutting means for mineral cutting machines This invention relates to a cutting means assembly for a mineral cutting machine, comprising a cutter pick having a longitudinal axis and a bore formed in the shank of the pick and extending transversely to said axis, a holder in which the cutter pick is removably mounted by means of its shank and which has two bores which are substantially in axial alignment with the bore of the cutter pick, and a member for axially retaining the cutter pick in the holder, which member is located in the transverse bore of the cutter pick and supported in the bores of the holder.

Variously constructed devices are known for axially retaining and locking cutting picks in the holders of endless cutting chains, or cutting drums and other carriers. In the case of cutting picks of rectangular shank cross-section the cutting pick is preferably locked axially in the shank-enclosing holder by constructions in which the holder and pick stem have a bore extending transversely of the direction of insertion of the pick in the holder, a transverse pin connecting both members being disposed in such bore. The transverse pin, acting as a retaining member and locking element, can be, for example, a notched pin or a transverse pin disposed askew in a rubber bush.The latter construction does not include a transverse bore in the pick holder, but a recess which produces a bayonet-type closure and in which the skew, resiliently mounted transverse pin is inserted (Federal German Utility Models 1949 209 and 1955 509; Federal German Patent Specifications Nos. 12 708 and 12 43 606; and British Patent Specification No. 11 82 661).

These cutting pick locking devices share the disadvantage that securing and releasing the cutting pick in the holder is a laborious process which can be carried out only with the aid of auxiliary tools. In another known cutting pick locking device a locking pin, which can be moved into an operative position as a linch pin, extends transversely of the direction of insertion through the pick holder and cutting pick shank. The linch pin is secured in position by spring rods which are disposed transversely of the direction of insertion of the linch pin and so engage behind a head portion of such pin that it cannot be released from the locking position (Federal German Utility Model No. 06 816).

One disadvantage of this type of securing is that releasing is a laborious operation which can be carried out only using auxiliary tools. This is partly due to the fact that such type of locking gets very dirty from the use of such tools and therefore easily jams.

U.S. Patent Specification No. 2965365 discloses a cutting pick locking means having a transverse pin which is disposed in the pick holder and engages partly in a notch-like recess in the pick shank, and is retained on both sides in resilient, e.g., rubber bushes, so that the transverse pin acts resiliently.

The cutting pick is inserted by pressing to one side the resiliently retained locking pin by a wedge surface which is provided on the pick shank and rises in the direction of insertion, whereafter the pick shank is latched into the locking notch. In this case also the locking can be released only by using suitable special tools, so that it is difficult to exchange the cutting picks.

Moreover, due to dirtying and the ageing of the rubber parts, such locking arrangement loses its efficiency of functioning relatively quickly, so that the cutting pick is lost under rough operating conditions.

British Patent Specifiction No. 11 55 602 discloses a cutting pick locking arrangement in which the locking element is formed by a helical spring which is disposed in the pick shank and engages in a recess with which the pick holder is formed and which is constructed in the manner of a bayonet-closure and is open towards the pick head in the direction of insertion. Such locking system also is suitable only for light cutting operations and calls for the use of auxiliary tools, being moreover liable to dirtying, with consequent adverse effect on operation, as a result of the upwardly open recess in the cutting pick holder.

It is an object of the invention to obviate the disadvantages of the known retaining and locking arrangements, to simplify the construction and manufacture of the device for axially locking the cutting pick in its holder, and to make the locking arrangement easy to service and reliable in operation even when dirty.

Another object of the invention is, while retaining the advantage of axially retaining and locking the cutting pick in its holder by means of a retaining member, to construct such retaining member, acting as a locking element, in a simple and inexpensive manner and so to adapt its function that it always remains reliable, even under rough operating conditions, and is easier to handle for securing and releasing.

To this end, the present invention consists in a cutting means assembly for a mineral cutting machine, comprising a cutting pick having a longitudinal axis and a bore formed in the shank of the pick and extending transversely to said axis, a holder in which the cutter pick is removably mounted by means of its shank and which has two bores which are substantially in axial alignment with the bore of the cutter pick, and a member for axially retaining the cutter pick in the holder, which member is located in the transverse bore of the cutter pick supported in the bores of the holder, the retaining member being hooked-shaped and comprising a shorter securing arm and a longer locking arm which engages through the cutter pick shank and has one or more humps.

According to optional features of the invention the hook-shaped retaining member is made of spring wire; the locking arm which engages through the shank of the cutting pick is bent once or several times, preferably in w-shaped form.

According to another optional feature of the invention the transverse bore in the shank of the cutting pick is offset in the longitudinal direction of the shank in relation to the bores in the holder.

The construction of the retaining member according to the invention and its arrangement in the bores in the holder and the shank of the pick can be produced by very simple technological means and is therefore inexpensive, and represents a very simple, reliable way of locking the tool parts to be interconnected.

As required, the locking arrangement can be put into effect without having to use special tools. To loosen or release the locking device it is enough to have available gripping tongs, such as a mechanic always has amongst his tools.

In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate diagrammatically and by way of example an embodiment thereof, and in which Figure 1 is a side elevation of the cutting pick holder with inserted cutting pick and retaining member moved out of the securing position, Figure 2 is a cross-section, on the line I-I of figure 1, but with the retaining member moved into the locking and securing position, and Figure 3 is a side elevation of the retaining member.

A shank 3' of a cutting pick 3 has a rectangular cross-section and is inserted in conventional manner in an aperture 2 in a cutting pick holder 1. The cutting pick 3 has a longitudinal axis x - x. The cutting pick holder 1 and the pick stem 3' are respectively formed with transverse bores 4 and 5 which are substantially in alignment with one another, but are axially offset in the longitudinal direction of the pick shank 3'. A hook-shaped retaining member 6, for example of spring wire, comprises a locking arm 7 and a securing arm 8. The central portion of the locking arm 7 is formed with one or more humps 9 preferably formed by one or more bends in w-shape.

In the locking position the securing arm 8 of the retaining member 6 engages positively in a recess 10 in the cutting pick holder 1 to secure the retaining member 6 against the locking system becoming loosened.

The locking and securing of the cutting pick in the holder is effected as follows: When the cutting pick stem 3' has been inserted in the aperture 2 in the pick holder 1, the retaining member 6 is introduced through the transverse bores 4 of the holder 1 and the transverse bore of the pick shank 3', as shown in Figure 2. Then the raining member 6 is pivoted out of the introduction and locking position A (Figure 1) in the direction B of rotation, until the arm 8 has taken up the securing position C (Figure 1). In this position the retaining member 6 is forced in the direction of its longitudinal axis, against the force of the spring tension imparted to the retaining member 6 by being pivoted out of position A into position C, into the transverse bores 4,5 until the securing arm 8 has arrived in the securing position in the recess 10, as shown in Figure 2.

Claims (5)

1. Cutting means assembly for a mineral cutting machine, comprising a cutter pick having a longitudinal axis and a bore formed in the shank of the pick and extending transversely to said axis, a holder in which the cutter pick is removably mounted by means of its shank and which has two bores which are substantially in axial alignment with the bore of the cutter pick, and a member for axially retaining the cutter pick in the holder, which member is located in the transverse bore of the cutter pick and supported in the bores of the holder, the retaining member being hook-shaped and comprising a shorter securing arm and a longer locking arm which engages through the cutter pick shank and has one or more humps.

2. An assembly according to claim 1, wherein the hook-shaped retaining member is made of spring wire.

3. An assembly according to claim 1 or 2, wherein the locking arm which engages through the cutting pick shank is bent once or several times, preferably in w-shaped form to provide said hump or humps.

4. An assembly according to any of the preceding claims, wherein the transverse bore in the cutting pick shank is offset in the longitudinal direction of the shank in relation to the bore in the holder.

5. A cutting means assembly for a mineral cutting machine, substantially as herein described with reference to and as shown in the accompanying drawings.