US3406471A

US3406471A - Digger tooth locking pin

Info

Publication number: US3406471A
Application number: US598451A
Authority: US
Inventors: Duplessis Gerard
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-08-11
Filing date: 1966-12-01
Publication date: 1968-10-22
Anticipated expiration: 1985-10-22

Description

Oct. 22, 1968 G. DUPLESSIS 3,406,471

DIGGER TOOTH LOCKING PIN Filed Dec. 1, 1966 PATENT AGE/V7 United States Patent ice The presentinvention "relates to two-partdigger or excavating teeth for the bucket of power shovels andthe like and, more specifically, to a locking pin of improved together. v V Excavating teeth of the cha'racterdescribed consist of an adapter having a 'forwardly protrudingtapered nose, on which is fitteda tooth point for receiving the nose. 1

The tooth point is provided with aligned openings adapted to register with a transverse bore made in'the nose for receiving a locking key or pin, which maintains and locks the tooth point in position on the nose. A block of compressible material is-positioned in a cavity within the nose and protrudes into'thebore "to engage and press the locking pin so 'as to prevent accidental removal or displacement of the pin.-'-However,

design for securing the two parts of "the excavating tooth due to the high stresses and forces impartedto the nose and tooth point during digging; due also tothe fact that the tooth point and adapter are cast metal pieces which therefore, are not'manufactu'red to very close tolerances; and, finally, due to the fact of metal creeping especially of the tooth point during working, displacement of the locking pin still frequently happens, resulting in break: age of the adapter and/or tooth point, or resulting in a locking pin which is impossible to remove for replacing the worn tooth point. i Y

The general object of the present invention resides, therefore, in a locking pin whichis of improved design such that when in proper locking position, it 'is"pra'c tically impossible for the locking pin to'become' acci dentally dislodged from its intended'operative' position and which yet can'berelatively'easilyremoved is desired to replace the worn-out tooth point.

A more specific object of the present invention resides in the provision of a locking keyor pin of the character described, which is' provided with'an upwardly facing having a tapered socket step at its back face topreventdisplacement of the locking pin upwardly and which isprovided at its front face with anotched medial rib of less .widthz than-the-total width of the front face of the pin,-,-said notch being characterized by the fact that the bottom thereof'iswoextensive with the front face of the pin, whereby the pres- F sure, namely the force per unit area, exerted by the compression block on the pin is much greater when the pin is forced out of its normal positionandsengagesonly the rib than when it is in its normal-positionyinfwhich position the force exerted by the bolck on the pin extends over the entire width of the front face of the pifilaTherel fore, the friction is greater. in the above-noted displaced position and the pin is positively maintained in its iritende'd operative position, so that there is assurance that the key will never become improperly positioned resulting in breakage of the adapter or tooth point, or of the distortion or bending of said elements, such that it would be impossible to remove the locking pin.

The foregoing and other important objects ofthe present invention will become more apparent during the following disclosure and by referring to the drawings, in which:

FIGURE 1 is a partial view of an adapter, tooth point, locking pin and retaining compressible block, shown partially in elevation and partially in longitudinal section;

- axis. Said face portion 9 is straight and fiat.

3,406,471 Patented Get. 22, 1 968 FIGURE 2 is a side elevation ofthe lockingpin; FIGURE 3 is a front elevation of the locking pin; F FIGURE 4 is a partial top plan view of. the assembly of'FIGURE 1;and '1 r FIGURE 5 is a partial 5-5 of FIGURE 1. 4

Referring now more particularly to the drawings in which like reference characters indicate like elements throughout, the locking pin P in accordance with the present invention consists of an elongated four-sided bodyfihaving substantially fiat and parallel lateral faces 1, substantially flat front face 2 andba'ck face 3,a substan-' tially flat top face 4 downwardly and forwardly inclined relative to the long axis of the pin, and a roundedlower end face 5. The four longitudinal edgesof the pin are bevelled, as shown at 6 and 7,*-for the front bevelled' edges' and back bevelled edges respectively and, similarlygthe' lateral edges of the top face 4 are bevelled as shown-at 8. :c The upper zone of the pin P forms a recessed back face portion 9 with respect to the remaining portion'of back face 3, to thereby define an upwardly facing 'step 10 at substantially right angles to the long axis of the pin P. The recessed face portion 9 is upwardly forwardly inclined with respect to the long axis of pin P, so as to make angle of between 7 and 10 degrees with said long plan section taken along line Thelower portion of front face 2 is downwardly and rearwardly inclined, as shown at 11, so that the corre* sponding lower end portoin of the pin is tapered towards lower end face 5. I

A longitudinally extending central rib 12 protrudes forwardly from front face 2 and extends over the major part of the length of said front face. More particularly, rib 12 defines an upper portion 13 and a lower portion 14 separated by a curved notch '15, the bottom of which is coincident with the front face 2, so as to lie in a sur face having the full width of front face 2, contrary to -the remaining surface portion of notch 15 which only has the width of the rib 12, the latter being about /3 the width of face 2. I The lower rib portion 14 forms a half-part of notch 15 and gradually downwardly tapers to merge with the front face 2 at the junction thereof with the lower front face 11. Actually, the front face of the lower rib portion -14 is aligned with lower face portion 11.

Upper rib portion 13 is of uniform thickness so that its front face is parallel with front face 2 and extends right up to the top face 4 of pin P, such that the top edge of the upper rib portion 13 forms the continuation of said top face 4.

The locking pin in accordance with the invention is used for locking the two parts of an excavating tooth, such as shown in the drawings. Said excavating tooth comprises an adapter 20, adapted to be removably secured to the lip of a bucket of a power shovel or the like and having a forwardly protruding integral tapered nose 21, on which is removably fitted a tooth point 22 having a tapered socket for receiving nose 21. i' A In the fitted position. of the tooth point on nose 21, the free edges 23 of the tooth point are slightly spaced from the shoulders 24 defined between nose 21 and adapter main body 25.

Tooth point 22 is provided with aligned top and

bottom holes

27 and 28, respectively, adapted to register, when the tooth point is in fitted position, with a bore 29, made through nose 21, and opening at the top and bottom faces of said nose 21.

In the front face of bore 29 is defined a groove 30 opening at the top and bottom faces of nose 21 and in the bore 29. Groove 30 has a width smaller than the width of bore 29 and is centrally located with respect to said boressueh that -the groove -30 defines shoulders-" move 'th'e top-ofthe" pin forwardly' in orderto" help clear 31 on each side thereof, said shoulders constituting the front face of the bore 29.

A block of compressible material, shown 'at 32, is located within groove 30 and is tightly fitted therein. Preferably, the block- 32 has a dovetailed base portion 33 engaging with a dovetailed bottom portion of the recess 30, in order to prevent disengagement compressible material 32. Said block -32 is provided vat mid-length with a'boss 34 protruding within bore 29 and-in which ispreferably embeddeda cylindrical metal block, not shown, forming a .Wear surface forengagement with the locking pin. 1

In the assembled position of the tooth point '22 on nose '21, the top hole 27 is forwardly offset with respect to bore 29, such that the back wall of top hole 27 is for- Wardly disposed ,With respect to the back wall of bore of theblock of 29 so as to form a downwardly facing step 35, atthe junction of.the tooth point with the nose. -,Upo n insertion of the lowerpointed end 5 ofthe locking-pin through the top hole 27-of the tooth point 22 and then through bore 29,;with the locking pin in a downwardly and backwardly inclined position, the front face 2 of the pin at the lower end thereof engages the top edge ,of the front face 31 of the bore 29 on both sides of the compressible block 32, and the tapered lower face portion 11 engages the top edge of the compression block 32 and initiates compression of said block. The back face 3 of the pin engages the back face of the top hole 27 and the pin, during said initial portion of the insertion, being in metal-to-rnetal contact with the nose and tooth point 22, produces a firm fitting of the tooth point on the noses Hammering of the locking pin causes the boss 34. of the compressible block 32 to slide on the lower rib portion 14 until said boss engages notch 15. Rib 12 compresses block 32 and engages groove 30. Step of the locking pin snaps underneath step 35 of tooth point 22. In the fully inserted position of the locking pin, as shown in FIGURE 1, the latter is prevented from accidentally moving upwardly because step 6 engages step 35 in metalto-metal contact, thereby latching the locking pin against upward movement, and also boss 34 engages notch 15 of e the locking pin, which forms a second latching means for the locking pin, the lower rib portion 14 preventing upward displacement of the pin.

Conversely, the locking pin is prevented from downward movement because the boss 34 of the compressible block 32, engaged in notch 15, abuts the upper rib portion 13., t

The block 32 exerts a balanced rearward force on the top and bottom of the tooth point. 7

In the fully inserted position of the pin, the front face of the latter is free of any contact with the front face of the

openings

27 and 28.

, The locking pin is relatively easily removed by hammering its lower end 5, whereby step 10 will finally clear stop 35 and boss 34 of the block 32 will clear the lower 1 rib portion 14.

If, for any reason, difficulty is experienced in having step 10.,clear step 35, a screwdriver or other implement can be wedged between the back face of top hole 27 and the inclined recessed back face portion 9 of the pin to step 10.

Due to the above-noted latching feature of the locking pin in accordance with the invention, to prevent both downward and upward rnovement of the latter from its intended position, it'has been found that the pin in accordance with' the invention remains in 'position despite heavy stressesto which the digging tooth is subjected dursus '1 While a preferred embodiment in accordance with the present inventionhas been illustrated and described, it is understood that various modifications may be resorted to without departing from, the spirit and scope of the appended claims. v v

- What [claim is:

1. Alocking pin for a two-part excavating tooth, comprising an elongated solid four-sided body having substantially. fiat lateral faces and having front and back faces, a pointed lower end and a top end face, said, back face having. a recessed upper face portion defining an upwardly facing step located nearer said topface than said lower end, a longitudinal rib protruding medially of said'front face and extending from said top end facedownwardly-toward said lower. end below the level of said step, saidrib having a notch made therein intermediate itsendsv and disposed below the level of said step, the bottom of said notch coinciding with a surface extending substantially the full width of said pin.

-. 2. A locking pin as claimed in claim 1, wherein said recessed upper face portion is upwardly forwardly inclined with respect to the longitudinal axis of said pin.

3. A locking pin as claimed in claim 1, wherein said rib has a width equal to about one-third of the total width of said body.

4. A locking pin as claimed inclaim 1, wherein said notch is locatedat about substantially midlength of said yp 5. A locking pin as claimed in claim 4, whereinthe portion of said rib below said notch has a front face downwardly tapering and merging with the front face of saidbody at a point short of the lower end of said body, the front face of said body being inclined downwardly and rearwardly from the point of junction of the front face of said rib,with. said front face of said body to the lower end of said body, said inclined front face portion being in alignment vwith the inclined front face of the lower rib portion. .1

ReferencesiCited v 1 UNITED STATES PATENTS 2,674,816 4 /1954 Daniels-ct al. 37-442 2,904,908 9/ 1959 Ratowski 37-142 2,982,035 5/1961 Stephenson' 3 7142 2,990,634" 7/ 1961 Eyolf son 37- 142 2/1968 Judkihs et 'al. 37-142 V I ,,F OREIGN PAYTENTSY 1;: 565,417: 11/1944 England; 641,404 5/1962- Canada.

aonER-"r nt-ruLrnnvgrl-imar Exam i ner.

Claims

1. A LOCKING PIN FOR A TWO-PART EXCAVATING TOOTH, COMPRISING AN ELONGATED SOLID FOUR-SIDED BODY HAVING SUBSTANTIALLY FLAT LATERAL FACES AND HAVING FRONT AND BACK FACES, A POINTED LOWER END AND A TOP END FACE, SAID BACK FACE HAVING A RECESSES UPPER FACE POTION DEFINING AN UPWARDLY FACING STEP LOCATED NEARER SAID TOP FACE THAN SAID LOWER END, A LONGITUDINAL RIB PROTRUDING MEDIALLY OF SAID FRONT FACE AND EXTENDING FROM SAID TOP END FACE DOWNWARDLY TOWARD SAOD LOWER END BELOW THE LEVEL OF SAID STEP, SAID RIB HAVING A NOTCH MADE THEREIN INTERMEDIATE ITS ENDS AND DISPOSED BELOW THE LEVEL OF SAID STEP, THE BOTTOM OF SAID NOTCH COINCIDING WITH A SURFACE EXTENDING SUBSTANTIALLY THE FULL WIDTH OF SAID PIN.