JPH08253958A - Exchanging point of excavation tooth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect an adaptor and a lock pin from abrasion. SOLUTION: An excavating tooth is assembled by fitting a point A' on an adaptor nose B" and by inserting a lock pin C" between them. In this state, the opposite ends of the lock pin engage respectively with an upper projecting part 29 and a lower projecting part 28 of an ear part 25 provided on one side wall of the point A', while the center of the lock pin engages with the front wall of a groove formed in the adaptor nose B". The ear part 25 extending to the rear of the point A' so acts as to protect an adaptor and the lock pin C".

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The excavating tooth of the present invention relates 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.

[0002]

2. Description of the Prior Art In U.S. Pat. No. 4,761,900, as shown in U.S. Pat. No. 4,353,532, HELILOK is commercially available worldwide.
A new locking device is provided to replace the U-shaped fitting used on the brand name tooth. US Patent No. 4,
No. 761,900 uses a drive penetrating pin that is held in place by a plug member or keeper that extends laterally across the length of the adapter so that it is not distorted by impact loads. U.S. Pat. No. 4,761,
The No. 900 vertical locking pin is clamped in place by an ear ridge at the rear of the point that 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.

[0003]

The present inventor is able to achieve a sufficient improvement during operation by using a pair of vertically spaced protrusions on the point ears regardless of the degree of curvature of the pin. Found.

By using spaced protrusions on the points, a point and nose assembly shape has been created which provides 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 disadvantage of the nose that holds points is
It is caused by wear of the operating nose to fit the point into the nose so that it becomes loose enough to fall or break.

[0006] 2. Fatigue nose structural defects.

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

[0008]

[Means for Solving the Problems] Regarding wear of the nose,
The arrangement of the present invention reduces the bearing pressure of points on the nose by providing a long bearing surface, thereby reducing the wear rate of the nose and the consequent loosening of the point fit. 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. U.S. Pat. No. 4,761,90
The No. 0 pin creates 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 projections of this invention cause the point to sway. Allows a pin shape that can absorb movement. This rocking is similar to US Pat. No. 4,761, as in a rolling analogy to a sliding block.
Compared to the No. 900 configuration, 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.

Obviously, a tight fit is required to keep the point in place on the adapter, but movement of the point relative to the adapter nose under heavy impact loading (US Pat. No. 2,919). , 506, No. 3,0
79, 710), and it is a fact that tightness decreases in proportion to this. U.S. Pat. No. 4,33535
The No. 43 basic helilock tooth system is capable of supporting and retaining points on the nose after a significant amount of slack has resulted from the nose wear. In this regard, US Pat.
It is superior to other tooth systems such as the 761,900 tooth system and the tooth system of this 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.

With respect to nose fatigue defects, the protruding nose of the nose can be eliminated by the use of two spaced apart protrusions on the sidewall extending posterior to 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.

[0011] The main advantages are the achievement of a tight fit, which has hitherto not been possible in the adapter, the elimination of stress concentrations at the joint between the handle and the nose of the adapter, and the achievement of a large point for the nose support length, There is.

A point with vertically spaced rearwardly extending upper and lower protrusions is similar to that in US Pat. No. 4,326,348, where the ear action provides cooperative stability with the ear canal. Already used in.

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.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, the teeth, helilock "HELILO" of U.S. Pat. No. 4,353,532.
“K” (product name) is shown. This tooth is point A
And an adapter having a nose portion B and 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 the difficulties encountered in removing the U-shaped lock C, which is solved by the use of the drive through pin C'of US Pat. No. 4,761,900, as shown in FIG. There is. US Patent No. 4,76
A particularly preferred feature of the 1,900 configuration was the use of an unstrained keeper or side plug D. The tooth point in FIG. 2 is the same as the tooth point in FIG.
Is attached. However, the adapter nose of FIG. 2 is different from the adapter nose of FIG.
Is attached. As mentioned above, the lock pin has been modified, so that the drive feedthrough pin of FIG. 2 is labeled C '.

According to the present invention, all of the points, the adapter nose and the lock pin are changed, and the reference numeral A ',
B ″ and C ″ are attached, but the keeper is not changed,
Therefore, the reference numeral D is attached.

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 points are indicated by dotted lines and are labeled 22
Is attached and is in a static state without impact.

A downwardly directed impact load or stress, as shown schematically by dotted line 23, causes 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 as shown in FIG.
The advantage is that it does not wear the front wall 24 of the nose groove which engages the middle part of the.

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 important of which is a spaced lock on the point. Providing a support surface for the pin.

[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 provided with the socket 27 so as to provide the ears 25 and 26. It extends beyond and behind. At the rear ends of these ears 25, 26, an integral upper projection 29 and lower projection 28 for the ear 25 and an upper projection 3 for the ear 26 are provided.
1 and the lower protrusion 30 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. These protrusions 28, 2
All 9, 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 top 33 of the upper projection 31 is shown.
And the vertical spacing between the bottom 32 of the lower protrusion 30 is the rear end, that is, 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 permits structural strength and an integral projection of appropriate length from the upright point of the support surface.

In the description, the inner surface 34 of the projections 30, 31 (corresponding to the projections 28, 29) as shown in FIG.
Reference numeral 35 is a partially inclined surface provided for the minimum clearance around the nose cone surface E in FIG. This is the sixth
Shown clearly in the figure, the plane E'is an extension of the nose cone rearward with respect to the part of FIG. When assembling and disassembling the points on the nose, these protrusions 30, 31
The inwardly sloping surface of must define the nose cone and the 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 surfaces of the protrusions, that is, the inner surfaces 34 and 35 are exactly circular, but a sufficient effect can be achieved even with a straight inclined portion.

Referring to FIG. 5, in the recommended structure,
The pair of frontward facing walls 36 and 37 are the lock pins 2
1 is a part of a circular arc surface of strong engagement with both longitudinally spaced end portions of the recessed trailing edge 38 of FIG. Only one pair of protrusions engages near the two ends of the lock pin in a given assembly, the other set of protrusions has the purpose of allowing point attachment 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 projection walls 36, 37 or the corresponding set of projections 28, 29. Therefore, if the locking pin 21 is not assembled on the nose and is placed in contact with the arcuate surfaces of the walls 36, 37 of the protrusion,
Partial contact is made near the ends of the projection surface, such as at the bottom 32, top 33. Due to the assembly of the locking pin on the point and nose assembly, this contact of the locking pin on the arcuate surface of the protrusion results in a forward projection of the nose groove 40 with the front wall 24 as shown in FIGS. Through the contact of the profiled edges 39, the pins become more flexible because they come to flex. Finally, under the working load received at the point during operation,
Since the pin is more flexible, the curvature of the concave trailing edge 38 substantially matches the curvature of the arcuate surfaces of the projection walls 36, 37 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 an angled break in the forward facing wall 36, 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 Lock Pins Instead of using the ears 42 of FIG. 2 for support on the new lock pin C ", the present invention provides a nose support as shown in FIGS. The face 24 of the front wall of the groove 40 is used, the nose support surface being planar with respect to the groove 140 as shown at 24 in FIG. 8 or as shown at 124 in FIG. Nominally, the locking pin bears against the front faces 24, 124 of the nose near the longitudinal mid-face of the nose, but the support moves above and below the mid-face 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 is designated by reference numerals 44 and 45 in FIGS.
Therefore, in FIG. 9, reference numerals 144, 14 correspond to the protrusion 143.
As is clear from what is shown at 5, the top and bottom are made with a nose. 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. Front wall face 2
4 has a recess 47 to accommodate insertion of a 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-eared point structure of FIG. 11 with the nose of FIG. 9, and this tooth is primarily used for dredging and cannot be reversed. The structure of the protrusions 28, 29 is the same as that of FIG. 3, but the ears forming the protrusions 30, 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 shown in FIGS. In comparison, it differs from pin C ', which facilitates the required rocking action which minimizes nose wear on surface 24 of the front wall.

Another configuration of the lock pin 221 is shown in FIG. The ears of the point of this configuration are approximately the same length as the rear diameter of the socket 27 of the point, but the walls 236, 237 of the forward facing protrusions are not arcs and the walls 236, 237 of these protrusions are sandwiched. Flat and parallel for use with mold locking pins. This sandwich type lock pin is a steel plate 248, 250 forming a rubber core 249, as has been used industrially for many years.
And in layers. This configuration is the front wall surface 2 of the nose groove
Although it does not make a suitable rocking engagement with 24, it has the advantage of an application that is suitable for light work and does not require a plug D. The lock pin of the assembly is held by the rear projection 251 of the inner projection walls 236 and 237 of the projections 228 and 229 and the rear steel plate 248 layer.
Provided by engagement with. 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 those skilled in the art without departing from the spirit and scope of the invention. .

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a tooth portion of US Pat. No. 4,335,532.

FIG. 2 is an exploded perspective view of a tooth portion of US Pat. No. 4,761,900.

FIG. 3 is an exploded perspective view of a tooth portion of the present invention.

FIG. 4 is a plan view of the assembled member of the present invention.

5 is a partially cutaway side view of the assembly of FIG. 4 taken along line 5-5 of FIG.

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 is a schematic side view of a nose with points shown in no shock and in shock.

FIG. 8 is a side view of the adapter nose portion of the embodiment of the present invention shown in FIGS. 3 to 7.

9 is a side view similar to FIG. 8 of another embodiment of the invention in which the nose support surface for the pin is arcuate.

10 is a perspective view of the nose of FIG. 8 viewed from the left rear.

FIG. 11 is a perspective view of a modification of the point of the present invention in which an ear portion extending rearward is provided only on one side wall.

FIG. 12 is a schematic side view of a cross section of a modified example of a tooth assembly in which the teaching of the present invention is implemented.

[Explanation of symbols]

20 ... Adapter nose, 21, 221 ... Lock pin, 22 ... Point, 24, 124, 224 ... Face, 25, 26, 42 ... Ear part, 27 ... Socket, 28, 29, 30, 31, 43, 228, 229 ... Projection part, 32 ... Bottom part, 33 ... Top part, 34, 35 ... Inner surface, 36, 37, 236, 237 ... Projection wall, 38 ... Rear edge part, 40 ... Recessed part, 41 ... Inclined part, 46, 146 ... Keeper Openings, 248, 250 ... Steel plate, 249 ... Rubber core.

Claims (10)

[Claims] 1. A relatively rear end having a ground engaging edge at its front end and a socket at its rear end formed by a top wall, a bottom wall and a pair of side walls to receive the nose of the adapter. At least one comprising an elongated integral body
At the excavation tooth replacement point, where two side walls extend rearwardly beyond the top and bottom walls, the rearwardly extending side walls are spaced apart from one another to engage near the two ends of the locking pin. An excavation tooth replacement point having upper and lower protrusions near its top and bottom and acting to protect said lock pin. 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 the socket has a rear portion having a substantially circular cross section, and the top portion of the upper protrusion and the bottom portion of the lower protrusion are separated by a substantially diameter length of the circular cross section. Exchange point. 4. The upper protrusion and the lower protrusion 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 wall and the bottom wall, each sidewall having the protrusion. 7. The excavating tooth replacement point according to claim 1, wherein the upper protrusion and the lower protrusion each have a wall facing forward and the wall has an arc shape. 8. The excavation tooth replacement point according to claim 1, wherein the upper projection and the lower projection have walls facing forward, and the walls are flat. 9. The digging tooth of claim 1 in combination with an adapter having a nose 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.