JPH0692664B2 - Excavation tooth replacement point - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drill tooth of the present invention, and more particularly to a novel point which is an improvement of US Pat. No. 4,761,900 and an improvement of US Pat. No. 4,353,532.

Prior Art In U.S. Pat.No. 4,761,900, U.S. Pat.
As seen in No. 32, a new locking device is provided to replace the U-shaped fitting used on the teeth of HELILOK (trade name) commercially available all over the world. U.S. Pat. No. 4,761,900 uses a drive through pin that is held in place by a plug member or keeper that extends laterally, i.e., horizontally, of the adapter length so that it is not distorted by impact loads. U.S. Pat.No. 4,761,900
The vertical locking pin of the No. is clamped in place by an ear ridge at the rear of the point which cooperates with a pair of vertically spaced ridges on the adapter. These projections, which cooperate to hold the pins, are rearwardly generally arcuate, that is to say convex rearward facing sides.

SUMMARY OF THE INVENTION The inventor has found that a sufficient improvement in operation can be achieved by using a pair of vertically spaced protrusions on the point ears regardless of the degree of pin curvature. I found it.

By using spaced protrusions on the points, a point and nose assembly shape was created which provided an improved operating life of the nose. In the description, the end of working life of the digging tooth nose is most commonly determined by one or the other of the following two types of drawbacks:

1. The drawback of the point-holding nose is caused by the wear of the nose during operation to fit the point into the nose so that it becomes loose enough to fall or break.

2. Fatigue nose structural defects.

The improved nose operating life provided by the point and nose structure of the present invention is due to a reduced source of both types of defects.

With respect to nose wear, the construction of the present invention reduces the bearing pressure of points on the nose by providing a long bearing surface, which results in wear rate of the nose and consequent point fit. To reduce looseness. It also provides "rocking" type support of the pin retaining point to the nose so as to reduce wear of the lock pin bearing surface on the nose. The pin of U.S. Pat.No. 4,761,900 produces friction against the nose ear through the small up and down movement of the pin induced by the point under load, while the point-separated ear protuberance of this invention Permits a pin shape that can absorb the induced swing. This rocking is similar to the simple analogy of a rolling car to a sliding block, as in U.S. Pat.
Compared to the configuration of No. 1,900, the wear of the lock pin support surface of the nose is equalized to a gentle rate. Further, the construction of the present invention ensures that the nose pin support surface and the pin itself are completely protected by the side walls extending posterior to all external wear, i.e. abrasive dirt and wear from the rock excavated by the teeth. Make up.

To keep the point in place on the adapter,
It is clear that a tight fit is required, but there is a movement of the point relative to the adapter nose under heavy impact loading (see US Pat. Nos. 2,919,506 and 3,079,710) and tightness is proportional to this. It is true that it will decrease. The basic helilock tooth system of U.S. Pat. No. 4,335,543 is capable of supporting and retaining points on the nose after a significant amount of loosening has resulted from the nose wear. In this respect, it is superior to other tooth systems such as the tooth system of US Pat. No. 4,761,900 and the tooth system of the present invention. However, there is a limit of slack that a given tooth device, with the intensity of its application, may change to the point that it cannot support and hold. The operating life implied by the teeth of the present invention beyond this limit is extended.

Action For nose fatigue defects, the protruding nose of the nose can be eliminated by the use of two spaced apart protrusions on the sidewall extending behind the point. Such a protruding nose portion causes stress concentration. Therefore, such removal provides a large nose fatigue stress and permits the placement of long bearing surfaces (front walls). These have two advantages over compensating the slight loss of material in the nose to provide a new side lock pin recess.

The main advantages are the achievement of a tight fit in the adapter, which was not possible in the past, the elimination of stress concentrations at the adapter handle-nose joint and the achievement of a large point for the nose support length.

Points with vertically spaced rearwardly extending upper and lower ridges have already been used, as in U.S. Pat. No. 4,326,348, where the ear action provides cooperative stability with the ear canal.

The prior art does not teach the preferred operation of the spaced rearwardly extending projections which limit the locking pin in its original locked position.

The present invention will be described with reference to the accompanying drawings.

EXAMPLE Referring to FIG. 1, there is shown the tooth, Helilock “HELILOK” (trade name) of US Pat. No. 4,353,532. This tooth has a point A and an adapter with a nose part B,
It consists of a U-shaped lock C. This tooth structure is particularly suitable for forming a strong nose because there is no lock pin opening.

However, this tooth has difficulties in removing the U-shaped lock C solved by the use of the drive through pin C'of U.S. Pat. No. 4,761,900 as shown in FIG. A particularly preferred feature of the construction of U.S. Pat. No. 4,761,900 was the use of an untensioned keeper or side plug D. The tooth points of FIG. 2 are identical to the tooth points of FIG. However, the adapter nose of Figure 2 has been modified from the adapter nose of Figure 1 and is therefore labeled B '. As mentioned above, the lock pin has been modified, so that the drive feedthrough pin of FIG. 2 is labeled C '.

In accordance with the invention, all of the points, adapter nose and lock pins have been modified and labeled A ', B ", C", but the keeper has not been modified and is therefore labeled D.

The invention is based on the finding that the locking pin moves with the point when the point is under impact loading. This is apparent from the schematic diagram shown in FIG. In FIG. 7, the adapter nose is shown in solid lines and is labeled 20. The lock pin is also shown in solid lines and is labeled 21 in the non-impacted state. However, the point is shown in dotted lines and is labeled 22 and is in a non-impact rest state.

Downward impact loads or stresses, as shown schematically by dotted line 23, cause point 22 to pivot on adapter nose 20 in the shape shown by dotted line 22 '. The lock pin 21 likewise pivots to the position indicated by the dotted line 21 '. This is for the rocking or rolling motion shown previously, and has the advantage, as shown in FIG. 5, of not abrading the front wall 24 of the groove of the nose which engages the middle part of the locking pin 21.

In order to find the advantage that the pin moves with the point of the drilling rig under construction, several modifications of the locking mechanism have been made, one of the important ones being the support of the locking pin spaced apart on the point. It is to provide a surface.

[Point Protrusion on Lock Pin] First, as is apparent from the consideration of FIG. 3, in the illustrated embodiment, the side wall of the point A ′ is rearward beyond the socket 27 so as to provide the ears 25 and 26. Extends to. At the rear end of these ears 25, 26 is an integral upper projection 29 for the ears 25.
Also, a lower protrusion 28 and an upper protrusion 31 and a lower protrusion 30 for the ear 26 are provided. The protrusion 29 is shown in the lower right hand portion of FIG. 4, and the protrusion 31 is shown in the upper right hand portion of FIG. All of these protrusions 28, 29, 30, 31 are shown in FIG. These protrusions 28, 29, 30, 31 project inwardly and extend substantially at right angles to the longitudinal direction of the socket 27, that is, at substantially right angles to the inside of the teeth.

From FIG. 6 the vertical spacing between the top 33 of the upper projection 31 and the bottom 32 of the lower projection 30 is the rear end and the “nose cone” of FIGS. It will be appreciated that the face E is approximately the length of the rear diameter of the socket 27 having a circular cross section.

This relationship is advantageous in that it allows for structural strength and an integral protrusion of appropriate length from the upright point of the support surface.

In the description, the protrusions 30 and 31 (protrusions) as shown in FIG.
Inner surfaces 34, 35 (corresponding to 28, 29) are partially inclined surfaces provided for a minimum clearance around the nose cone surface E of FIG. This is clearly shown in Figure 6,
Surface E'is an extension of the nose cone rearward of the portion of FIG. In assembling and disassembling the points on the nose, the inwardly sloping surfaces of these protrusions 30, 31 must define the nose cone and extension surfaces E, E '. The combination of the flat, high point ears of FIGS. 3-7 and the circular socket / nose cone cross section provides point protrusions of appropriate dimensions outside of this inner boundary cavity.

In the present invention, the inwardly inclined surface of the protrusion, namely the inner surface 34
Although 35 is exactly circular, sufficient action can be achieved even with a straight slope.

Referring to FIG. 5, in the recommended construction, a pair of forward facing walls 36, 37 of the projection are recessed trailing edges 38 of the lock pin 21.
Is a part of an arc surface of strong engagement with both end portions spaced apart in the longitudinal direction. Only one pair of protrusions engages near the two ends of the lock pin in a given assembly, the other pair of protrusions has the purpose of allowing the attachment of points in the 180 ° rotated direction. This embodiment of rotating the point when it is about half worn is sometimes practiced when very sharp drilling features are required.

Prior to assembly, the curvature of the recessed trailing edge 38 of the lock pin 21 is less than the curvature of the set of arcuate surfaces of the walls 36, 37 of the projection or the corresponding set of projections 28, 29. Therefore, if the locking pin 21 is not assembled onto the nose and is placed in contact with the arcuate surfaces of the walls 36, 37 of the projection, then it will be near the end of the projection surface as at the bottom 32, top 33. To make partial contact. Due to the assembly of the lock pin on the point and nose assembly, this contact of the lock pin on the arcuate surface of the protrusion causes the nose groove 40 to project forward with the front wall 24 of the groove 40 as shown in FIGS. Through the contact of the profiled edge 39, the pin becomes more flexible because it comes to flex. Finally, the concave trailing edge allows the pin to flex further under the operating load experienced at the point during operation.
The curvature of 38 substantially matches the curvature of the arcuate surfaces of the walls 36, 37 of the protrusion for full contact.

Of course, this is the flexibility of the pin which produces a strong assembly force.

The drive of the pin to the point / nose assembly is facilitated by the sloping obstruction of the forward facing wall 36 of the protrusion as at 41 in FIG. When the entry end of the lock pin 21 passes over the inclined portion 41, the lock pin 21 is deformed or curved so as to be guided by the wall 36 of the protrusion facing forward.

[Nose support on the lock pin] To support on the new lock pin C ″, the ears shown in FIG.
Instead of using 42, the present invention uses the front wall face 24 of the nose groove 40 as shown in FIGS. The nose support surface is flat with respect to the groove 140 as shown at 24 in FIG. 8 or slightly arcuate as shown at 124 in FIG. Nominally, the locking pin is supported on the front 24,124 of the nose near the longitudinal midplane of the nose,
The support moves above and below the interface during impact stress.

The nose groove 40 is formed by an integral edge 43 as far as the rear wall is concerned, comparing FIGS. This protrusion 43
Are the reference numerals 44 and 45 in FIGS. 3 and 8, and the protrusion 14 in FIG.
The top and bottom are together with the nose, as is apparent from the numbers 144 and 145 for the 3. The arc of the front wall surface 124 of FIG. 9 is apparent from being tangential to the keeper opening 146 at the midpoint as compared to the relationship of the front wall surface 24 to the keeper opening 46 of FIG. is there.
The face 24 of the front wall has a recess 47 to accommodate the insertion of the keeper, see FIG.

Further, the protrusion 43 or 143 acts as a guide when the lock pin is attached. In this connection, it was chosen to use the single-ear point structure of FIG. 11 with the nose of FIG. 9, and this tooth is primarily used for dredging and cannot be reversed. Protrusion
The structure of 28, 29 is the same as that of FIG.
The ears forming 31 are omitted.

[Lock Pin] As shown above, the lock pin C ″ is that the lock pin used for the point of the present invention is curved forward, that is, normally curved, as compared with FIGS. Unlike pin C ', this facilitates the required rocking action which minimizes nose wear on face 24 of the front wall.

Another configuration of lock pin 221 is shown in FIG. The ear of the point in this configuration is approximately the same length as the rear diameter of the socket 27 of the point, but the wall 23 of the front-facing projection is
6 and 237 are not arcs and the walls of these ridges 236 and 237 are flat and parallel for use with sandwich type lock pins. This sandwich type lock pin is layered with steel plates 248 and 250 forming a rubber core 249, as has been used for many years in the industry. Although this configuration does not make a favorable swinging engagement with the front wall surface 224 of the nose groove, it has the advantage of being suitable for light work and requiring no plug D. The holding of the lock pin of the assembly is provided by the engagement of the inner protrusion walls 236, 237 of the protrusions 228, 229 with the rear protrusion 251 of the rear layer of steel plate 248. It will be clear here that corresponding protrusions are usually provided on both sides of the point, as in the corresponding depressions of the nose.

In the foregoing description, the detailed description of the invention is for purposes of illustration only and many modifications may be made by one skilled in the art without departing from the spirit and scope of the invention.

[Brief description of drawings]

1 is an exploded perspective view of the tooth portion of US Pat. No. 4,335,532, FIG. 2 is an exploded perspective view of the tooth portion of US Pat. No. 4,761,900, and FIG. 3 is an exploded perspective view of the tooth portion of the present invention. FIG. 5 is a plan view of the assembled member of the present invention, FIG. 5 is a partially cutaway side view of the assembly of FIG. 4 taken along line 5-5 of FIG. 4, and FIG. Sectional view taken along line 6-6 of the figure,
FIG. 7 is a schematic side view of the nose having a point shown in no shock and shock state, and FIG. 8 is a side view of the adapter nose part of the embodiment of the present invention shown in FIGS. 3 to 7. FIG. 9 is a side view similar to FIG. 8 of another embodiment of the present invention in which the nose support surface for the pin is formed into an arc.
FIG. 10 is a perspective view of the nose of FIG.
FIG. 12 is a perspective view of a modification of the point of the present invention in which an ear extending rearward is provided only on one side wall, and FIG. It is a figure. In the figure, 20: Adapter nose, 21, 221: Lock pin, 22:
Point, 24, 124, 224: Face, 25, 26, 42: Ear, 27: Socket, 28, 29, 30, 31, 43, 228, 229: Projection, 32: Bottom, 33: Top, 34, 35: inner surface, 36, 37, 236, 237: protruding wall, 38: rear edge portion, 40: dent, 41: inclined portion, 46, 146: keeper opening, 248, 250: steel plate, 249: rubber core.

Claims (10)

[Claims] 1. A front end portion having an edge portion for engaging with the ground,
A relatively elongated integral body having at its rear end a socket formed by a top wall, a bottom wall and a pair of side walls for receiving the nose of the adapter, wherein at least one side wall extends beyond the top and bottom walls. At the replacement point of the rearwardly extending digging tooth, the rearwardly extending sidewalls have upper and lower protrusions spaced apart from one another for engagement near the two ends of the locking pin, An excavating tooth replacement point having near its top and bottom, said locking pin pivotably engaging said nose. 2. The excavation tooth replacement point according to claim 1, wherein the upper protrusion and the lower protrusion extend inwardly from the side wall at substantially right angles to the socket for supporting the lock pin. 3. The digging tooth according to claim 2, wherein said socket has a rear portion having a substantially circular cross section, and a top portion of said upper protrusion and a bottom portion of said lower protrusion are separated by a substantially diametrical length of said circular cross section. Exchange point. 4. The upper projection and the lower projection have inwardly facing walls which are adjacent to each other and partially inclined so as to conform to the shape of the socket. Excavation tooth replacement point. 5. The upper protrusion and the lower protrusion each have a wall facing forward, and a part of a front wall of the lower protrusion adjacent to the upper protrusion is provided when a lock pin is attached. 5. The excavation tooth replacement point according to claim 4, which is inclined rearward so as to guide the lock pin. 6. The excavation tooth replacement point of claim 1 wherein both sidewalls extend beyond the top and bottom walls, each sidewall having the projection. 7. The excavating tooth replacement point according to claim 1, wherein the upper protrusion and the lower protrusion have walls facing forward, and the walls have an arc shape. 8. The excavation tooth replacement point according to claim 1, wherein the upper protrusion and the lower protrusion each have a wall facing forward, and the wall is flat. 9. The digging tooth of claim 1 in combination with an adapter having a nose provided with a groove extending forward to receive the lock pin and having a front wall for supporting engagement with an intermediate portion of the lock pin. Exchange point. 10. The adapter includes a horizontally extending recess aligned with the lock pin and having an elastic keeper for the lock pin in the recess, the recess extending inward from the groove. The excavation tooth replacement point according to claim 9.