US 3410010 A
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Description (OCR text may contain errors)
Nov. 12, 1968 T. A. RATKOWSKI 5 Sheets-Sheet 1 ed Oct. 5, 1965 IN TOR THOMAS A. R KOWSKI ATTORNEYS Nov. 12, 1968 T. A. RATKOWSKI 3,410,010
7 DIPPER TOOTH Filed Oct. 5. 1965 3 Sheets-Sheet 2 lww flu] INVENTOR. THOMAS A. RATKOWSKI BY MMfWMJQM- ATTORNEYS Nov. 12, 1968 RATKow$K| I 3,410,010
DIPPER TOOTH Filed Oct. 5, 1965 3 Sheets-Sheet 5 IN VENTOR. THOMAS A. RATKOWSKI ATTORNEYS United States Patent 3,410,010 DIPPER TOOTH Thomas A. Ratkowski, Chicago Heights, 11]., assignor to Abex Corporation, a corporation of Delaware Filed Oct. 5, 1965, Ser. No. 493,137 1 Claim. (Cl. 37-142) ABSTRACT OF THE DISCLOSURE Retention of the point on a dipper tooth having an adapter or holder is improved by confining a rubber block or the like in a unique cavity of the adapter and recessing the adapter to enable the retainer key to be wrapped about a portion of the block preliminaly to driving the key home.
This invention relates to dipper teeth, and more particularly to dipper teeth employed on digging and excavating equipment.
The present invention is of particular utility in securing a removable point or tip to an adapter or holder by a retainer key or pin. When securing a point to an adapter, a retainer key or pin is driven into a keyway, by repeated hammer blows on the retaining key, into a position to interlock the point on the adapter. In many instances, the point is removed, after wear on one side thereof, and reversed to expose the opposite side of the point to the greatest wearing forces. This reversal of the tooth requires removal of the retaining key and reinsertion of the retaining key to secure the point to the key after the point has been reversed. Usually, the retaining key is held in its interlocking position within the keyway by a resilient detent. The retaining key is driven into and from detenting engagement with its detent element during the installation, reversal and removal of the point. More particularly, for each point, the retaining key is usually driven into the keyway on three different occasions, namely, to secure the point when it is new, to reverse the point a first time, and to reverse the point a second time to return the point to its original orientation.
Since the point is subjected to tremendous forces and extreme environmental conditions, it is essential that the retainer key be properly positioned and held with sufficent detenting force to retain the key in its interlocking relationship during the use of the point. However, it sometimes occurs that the retainer key is not properly seated with a resilient detenting element, and the retainer key eventually works loose. Accordingly, an object of the present invention is to facilitate the proper seating of the detent element in interlocking relationship with a retainer key for a dipper tooth. A more specific object of the invention is to reduce the amount of displacing force on such a resilient detent element in the direction of key movement as the retainer key is being driven through a keyway in the point and adapter. Another object of the invention is to minimize the component of force tending to remove the resilient detent element from its seat in the adapter during insertion of the retainer key.
As will be appreciated from the foregoing, the driving of the retainer key in the keyway into detenting relationship with the resilient detent means exerts a force on the resilient detent means tending to displace it from its seat in the adapter. Where the resilient detent means is a rubber element secured within a seat cavity in the adapter, the force of the key on the rubber element has, on some occasions, caused tilting of the resilient detent element within its seat and the displacement of an interlocking node on the rubber element out of position for seatin properly within a detent recess in the retainer key. Thus, the retainer key is not always locked in po- Patented Nov. 12, 1968 sition and works loose while the equipment is in operation. Accordingly, another object of the invention is a novel resilient detent means particularly adapted to resist tilting and displacement of its node portion from a position for interlocking with the retainer key. Another and more specific object of the invention is to resist such tilting by a T-shaped detent element having transverse portions thereof engaging transverse walls in an adapter thereby holding the resilient element against such tilting movement.
In many cases, the resilient detent means has a short life and it is necessary to afford a new resilient detent means for each point replacement or even for each reversal of the key. Manifestly, this short life of resilient detent elements and the replacement of the resilient detent means are costly factors and results in undersirable expense including down time for expensive excavating equipment. Thus, another object of the invention is to reduce the occurrence of replacement of detent elements and the amount of down time caused thereby.
A further object of the invention is to improve the retention of a retainer key by providing an area on the key for expansion of a resilient element into and about a detent seat on said retainer key,
Another object of the invention is to wrap the key partially about the node of the detent element to facilitate the insertion of a key into aligned keyway openings in an adapter and point. A further object of the invention is to foster this wrapping of the retainer key by affording clearance space in the adapter to receive the nose of the key to permit its deeper insertion prior to exerting a downward component of force on the node of the detent element.
Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, shows preferred embodiments of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.
In the drawings:
FIG. 1 is a sectional view showing a point secured to an adapter by a retainer key secured in position in accordance with the preferred embodiment of the invention;
FIG. 2 is a sectional view of the point and adapter with the retainer key being inserted in the keyway prior to being driven into interlocking relationship of FIG. 1;
FIG. 3 is a plan view of the keyway and detent seat in the adapter;
FIG. 4 is a sectional view taken along the lines 4-4 of FIG. 3;
FIG. 5 is an elevational view of a resilient detenting element;
FIG. 6 is a plan view taken along the lines 66 of FIG. 5 in the direction of the arrows;
FIG. 7 is a plan view of a metal insert in said detent element;
FIG. 8 is an elevational view of the insert of FIG. 7;
FIG. 9 is an elevational view of a retainer key constructed in accordance with the preferred embodiment of the invention;
FIG. 10 is a plan view of FIG. 9;
FIG. 11 is a sectional view taken along the lines 1111 of FIG. 9 in the direction of the arrows; and
FIG. 12 is an end view taken along the lines '12-12 of FIG. 9 in the direction of the arrows.
Referring now to the drawings and more particularly to FIG. 1, there is illustrated the assembled relationship of a point secured to an adapter 11 by a retainer key 12 driven through a keyway 14 into engagement with a resilient detenting means 15. The point or tip 10 has a conventional wedged shaped socket 18 defined by wedged shaped walls 19 and 20 diverging outwardly and rearwardly and disposed for tight engagement with complementary shaped wedged faces 21 and 22 on the adapter 11.
When the key 12 is driven into the locking position of FIG. 1, a front face 26 on the key 12 is in tight wedging engagement with the opposed and spaced, inclined shoulders 27, FIGS. 1 and 3, of the adapter 11 and a rear face 28 on the key 12 is in tight wedging engagement with upper and lower bearing surfaces 29 and 30 on the point 10.
Thus, the key 12 holds the point 10 against sliding leftwardly, as viewed in FIG. 1, along the adapter 11 and keeps the wedge faces 19, 21 and 20, 22 in tight engagement. The detent means 15 holds the retainer key 12 in its position against moving out of the keyway 14 with its curved detent portion or node on a main body portion 25 of rubber seated in a complementary detent seat 42 on the key 12.
While the point or tip 10 is described as being attached to an adapter 11, it is to be understood that the point 10 could be the sole element of the tooth and could be directly attached to a lip of an excavating bucket or the like having a suitable keyway for receiving a retainer key 12 for a detent means 15. Thus, the present invention is not limited only to a point and adapter arrangement constituting a tooth; but also is applicable to other arrangements wherein a tooth is afforded by a single element directly connected to the lip of an excavating bucket or the like.
Initially, the retainer key 12 is inserted through the upper one of the keyway slots 32 in the point 10 with the lower end or nose 33 of the key disposed beneath the surface of a node portion 35 of the detent means 15, as best seen in FIG. 2. The retainer key 12 can be moved under simple hand pressure into the approximate position illustrated in FIG. 2, prior to driving the key by a suitable hammer. Heretofore, the retainer key of the prior art arrangements would be oriented in a much higher position and in a more generally vertical orientation as illustrated by the dotted outline of a key 12A, FIG. 2.
An important aspect of the present invention is the shape of the key 12 and the forming of an interior or recess wall 38 on the adapter between upper and lower shoulder walls 39 to receive a rounded portion 40 of the lower end 33 of the key 12 such that the driving of the key 12 downwardly by a hammer causes the key 12 to exert much of its force on the node 35 in the direction of the arrow A to compress the resilient body 25 toward the rear wall 24. By this construction, a smaller component of force is exerted in the generally downward direction on the node 35 tending to force the node 35 downwardly and to rotate the upper portion of the resilient body member in the direction of the arrow B. Thus, the key 12 of the present invention is so related. to the adapter 11 and detent means 15 that is is initially wrapped about the node 35 without applying a large force tending to unseat the detent means 15 as heretofore encountered when using an arrangement, such as exemplified by the driving key 12A, as will be explained immediately hereinafter.
The usual prior art practice is to afford a rear adapter wall 38A extending in the same plane as the shoulder wall 39, FIG. 2, for engagement by the nose 40A on the lower portion of the key 12A. It will be noted that the position of the key 12A is much higher and in a more vertical relationship above the node 35. Thus, the driving of the key 12A exerts a much greater downward force on the node 35 of the resilient detent means 15 tending to rotate the resilient detent means to rotate the upper portion thereof in the direction of the arrow B while driving the node portion 35 downwardly. In some instances, the node 35 was lowered sufficiently so that the node 35 would not properly seat within a detent seat 42 in a key 12A. When this happened, the detenting relationship would not be established and the node 35 would actually be exerting a force tending to lift the key 12A outwardly of the keyway 14. Then vibrations and forces applied to the point 10 would work the key 12 loose.
Another important aspect of the present invention is that the resilient detent means 15 is of a design and is related to a seat 44, FIG. 3, to resist the rotation in the downward movement of the node portion 35 when engaged and during the driving of the key 12 into position. More particularly, the seat 44 in the adapter 11 is of a generally T-shaped configuration having a throat 47 leading to curved, transverse seat portions 45 and 46 with rearward transverse wall 48 and 49 for engaging the complementary transverse wall 50 and 51 formed on the main body portion 25, FIG. 6, of the resilient detent means 15.
As best seen in FIG. 4, the curved transverse seat portions 45 and 46 are considerably wider at the upper and lower wedge surfaces 21 and 22 than at the medial portion therebetween.
Because the body portion 25 of the detent means 15 is a resilient material, it will tend to stretch and become of a lesser thickness across the throat 47 and to slide from the seat 44 and into the main keyway 14 when a large force is applied downwardly on the upper surface 53, FIG. 5, of its node portion 35. However, the transverse walls 50 and 51 of the present detent means 15 are sufficiently wide and of sufiicient strength to prevent the sliding of the upper portion of the detent means 15 rearwardly through the throat 47 into the keyway 14 during the driving of the key 12.
The node or detenting portion 35 of the resilient detent means 15 has a metallic reinforcing insert 55, FIGS. 6 and 8, which is a generally cylindrical body having a pair of spaced annular grooves 56 and 57. The insert 55 is disposed at the node portion 35 with the rubber body material completely encasing the node portion as is readily apparent from FIG. 6. The metallic insert 55 serves as a reinforcing member for the node portion 35 and is configured to seat within the detent notch 42 in the retainer key 12.
An important aspect of the present invention is an improved interlocking relationship between the detent means 15 and the retainer key 12. For this purpose, the retainer key 12 is provided with an upper groove or notch area 60, FIG. 9, disposed towards the head portion 61 of the retainer key 12 to receive a portion, FIG. 1, of the detent means 15. That is, the compression of the resilient body 25 of the detent means 15 at the node 35 forces the body 25 to assume the shape of FIG. 1, with a portion expanded into the groove 60. Compression of resilient body 25 of the detent means 15 by the node portion 35 being moved inwardly into the body 25, also causes the resilient body 25 to expand in a vertical direction, as viewed in FIGS. 1 and 2, to engage specially formed shoulder surfaces 66 and 67 formed along the interior wedge faces 19 and 20 of the point 10. More particularly, as seen in FIG. 2, the resilient body 25 in its unex panded state has its upper and lower faces 68 and 69 aligned with but spaced from the respective surfaces 66- and 67 of the point 10. However, when the node 35 is driven forwardly by the retainer key 12 to the position shown in FIG. 1, the upper and lower faces 68 and 69 of the resilient detent means move vertically and engage the respectively associated tooth faces 66 and 67 to provide additional holding force against the tilting or displacement of the detent retaining means 15.
The retaining key 12 is provided with a channel 70 for receiving the node portion 35 of the detent means 15. The channel 70 is formed by side walls 71 and 72, FIGS.
and 11 extending from the front face 26 downwardly to a bottom wall 76. The bottom wall 76 is inclined from the end 33 of key 12 to curved portion 78, FIG. 9, just prior to the detent receiving seat 42. Thus, when the retaining key 12 is inserted into the keyway 14, as viewed in FIG. 2, the node portion 35 is forced inwardly as the inclined surface 76 slides therepast. After repeated hammer blows the key 12 is driven deeper into keytway 14 to move the point 78 across the node 35, whereupon the rubber body 25, which is now under compression, is free to expand the node portion 35 rightwardly into the detent seat 42. Thus, the node portion 35 with the metallic insert 55 is seated in detenting relationship .in the socket 42 of the key 12, as best seen in FIG. 1..
During driving of the key 12 into the keyway 14, the inclined front face 26 of the key 12 slides along rearwardly inclined shoulders 27, FIG. 3, on the adapter 11. The front face 26 of the key 12 is sufficiently wide between upper sloped side walls 80 and 81, FIG. 11, of key 12 to engage simultaneously both of the shoulders 27 on the opposite sides of the throat 47 on the adapter 11. The upper sloped side walls 80 and 81, FIG. 11, of the key 12 are inclined to meet the lower side walls 82 and 83 at intersections 84 and 85 defining the maximum width of the key 12. The maximum width of the key 12 between the points 84 and 85 is less than the dimensional width between the opposed keyway walls 86, FIG. 3, in the keyway 14 of the adapter 11. The maximum transverse width of the key 12 is from a point 88, FIG. 9, to a point opposite on the rearward wall 28. From the point 88 an inclined surface 89 leads to the upper surface 90, which is adapted to receive the hammer thrust when driving the key into position.
From the foregoing, it will be seen that the present invention affords a novel manner of securing a point to an adapter. The detent element includes a transverse portion holding the detent element against tilting or rotational movement when a force is exerted thereon by a retaining key being driven into its position within the keyway. Also the adapter has a novel construction oriented to the key relative to the detent element to reduce the amount of displacing force on the resilient detent element as the key is being driven through the keyway. The retainer key is adapted to move into detenting engagement with the resilient detent element and is adapted to receive portions of the detent element which have expanded due to the compressing of the resilient detent element.
Hence, while preferred embodiments of the invention have been described and illustrated, it is to be understood that they are capable of variation and modification.
1. A dipper tooth comprising: an adapter having forwardly tapered nose portion, a replaceable and reversible point having a forwardly tapered cavity for receiving said tapered nose portion of said adapter, removable key means for locking said point on said adapter, spaced walls on said point having aligned apertures therein for receiving said key means, bearing surfaces in said point at said apertures for engagement with said key means, said adapter having a keyway opening for receiving said key means, said keyway having a recessed area permitting the end portion of said key means to move downwardly, said adapter having a substantially T-shaped cavity opening extending through said adapter into said keyway, said T-shaped cavity presenting a narrow throat portion opening into said keyway and an enlarged portion bounded by a pair of curved walls which are of narrowing width progressively from opposed outer ends of the T-shaped cavity, resilient means of complementary T-shaped cross-section disposed in said T-shaped cavity, said resilient means having a node portion extending into said keyway, a cooperating seat on said key means for seating engagement with said node portion of said key means, and said recessed area of said adapter being alignable with said node portion of said resilient means to permit said end portion to wrap around said node portion.
References Cited UNITED STATES PATENTS 2,846,790 10/ 1958 Davis et al. 37142 2,904,908 9/ 1959 RatkOwski 37-142 2,990,634 7/1961 Eyolfson 37-142 OTHER REFERENCES Roads and Streets, October, 1958, p. 70.
ABRAHAM G. STONE, Primkzry Examiner.
A. E. KOPECKI, Assistant Examiner.