Ulllted States Patent [19]
`Pippins
`
`[54] REPLACEABLE MACHINE PART
`RETENTION SYSTEM
`
`[76] Inventor: Sherlock Pippins, 18352 Dallas Pkwy,
`Suite 136-341, Dallas, TeX. 75287
`
`~
`
`[21] Appl. No.1 09/286,060
`[22]
`Filed:
`Apr. 5, 1999
`
`US006119378A
`[11] Patent Number:
`[45] Date of Patent:
`
`6,119,378
`Sep. 19, 2000
`
`2,635,366
`4,247,147
`4,663,867
`
`4/1953 Hostetter ................................. .. 37/459
`1/1981 Rettkowski .
`37/458X
`5/1987 Hahn et al. .
`37/459
`gain ----- -
`53377495 8/1994 Pippins .
`5,709,043
`1/1998 Jones et al. ............................. .. 37/458
`5,926,982
`7/1999 Keech et al. ............................ .. 37/458
`
`,
`
`,
`
`a n ....................................... ..
`
`7
`
`................................................
`
`Primary Examiner—R0bert E. PeZZutO
`A
`A
`F. _N. S
`H H & N.
`ttorney, gent, 0r zrm
`1r0, cavone, a er
`1r0
`
`[58] Field of Search ............................ .. 37/455, 456, 457,
`37/458, 459, 454; 172/772, 772.5, 701.2,
`7013
`
`[56]
`
`References Cited
`
`US PATENT DOCUMENTS
`
`[57]
`
`ABSTRACT
`
`_
`_
`_
`A system for rapid and easy replacement of sacri?cial
`machine parts, utilizing an adapter having a slot and a
`retainer pin ?tted With at least one spring-loaded ball bearing
`suitable for engaging the slot When the retainer pin is
`inserted into the adapter.
`
`9/1989 Emrich .................................... .. 37/459
`Re. 33,042
`2,618,873 11/1952 Hostetter ................................. .. 37/459
`
`2 Claims, 5 Drawing Sheets
`
`11
`
`\ \ \ \
`
`12
`
`101
`
`M
`
`3
`
`0
`
`’
`
`102
`
`‘I00
`
`1_
`
`/_/\200
`
`/
`
`“
`
`f
`
`,0,
`
`l:
`
`202
`
`207
`
`04
`
`CATERPILLAR EXHIBIT 1004
`
`Page 1 of 10
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 19,2000
`Sep. 19,2000
`
`Sheet 1 0f5
`Sheet 1 0f5
`
`6,119,378
`6,119,378
`
`
`
`Page 2 of 10
`
`Page 2 of 10
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 19,2000
`Sep. 19,2000
`
`Sheet 2 0f5
`Sheet 2 0f5
`
`6,119,378
`6,119,378
`
`FIG.3
`
`FIG. 3
`
`Page 3 0f 10
`
`Page 3 of 10
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 19,2000
`Sep. 19,2000
`
`Sheet 3 0f5
`Sheet 3 0f5
`
`6,119,378
`6,119,378
`
`FIG. 6
`
`
`
`3
`
`FIG. 7
`103
`
`M
`
`Page 4 of 10
`
`Page 4 of 10
`
`

`

`U.S. Patent
`US. Patent
`
`Sep. 19, 2000
`Sep. 19, 2000
`
`Sheet 4 0f5
`Sheet 4 0f 5
`
`6,119,378
`6,119,378
`
`FIG. 8
`
`0 __l
`
`203
`
`202
`
`207
`
`206
`
`205
`
`‘m
`
`/
`
`
`
`Page 5 0f 10
`
`Page 5 of 10
`
`

`

`U.S. Patent
`
`Sep. 19,2000
`
`Sheet 5 0f5
`
`6,119,378
`
`/203
`Q
`
`FIG. 10
`
`/\206
`
`"
`201/
`
`J
`202
`
`FIG. 10a
`/’T—
`
`207
`
`223
`
`7
`
`220
`
`k
`
`‘F
`
`22A
`
`FIG. 11
`
`221
`/
`/ q
`
`222
`
`*
`
`0
`
`225
`
`Page 6 of 10
`
`

`

`1
`REPLACEABLE MACHINE PART
`RETENTION SYSTEM
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`This invention relates to replaceable machine parts that
`are exposed to high Wear and repeated shock loading, such
`as teeth used on dragline buckets. Speci?cally, the system of
`this invention comprises a neW and improved retention
`system permitting easier and quicker changeovers of high
`Wear replaceable parts.
`2. Description of the Prior Art
`Digging and levelling apparatus such as draglines,
`backhoes, front-end loaders and like often use replaceable
`tooth assemblies Which are mounted on the tooth horns to
`provide sacri?cial parts that are exposed to the repeated
`shock loading and high Wear occasioned by the digging
`operation. In such systems, each tooth assembly typically
`includes a Wedge-shaped adapter Which mounts directly on
`the tooth horn of the bucket, shovel or alternative digging or
`scraping mechanism of the equipment. A Wedge-shaped
`tooth point is frontally seated on and rigidly pinned to the
`adapter for engaging the material to be excavated.
`Attachment of the tooth point is typically accomplished
`by means of one or more inserts Which are inserted into
`insert cavities in an adapter. The inserts are internally
`threaded to accommodate a bolt that secures the tooth to the
`adapter. Installation and removal of teeth secured using such
`a system requires substantial time and effort, since the tooth
`point bolts must be screWed in and unscreWed When the
`tooth is to be replaced, operations Which requires using a
`poWered impact Wrench. Moreover, the use of such a tool
`presents the danger of over-torquing, resulting in damage to
`the threads and possible personal injury to the operator.
`
`SUMMARY OF THE INVENTION
`I have discovered that by using a pin featuring spring
`loaded balls along the shank instead of a threaded bolt, along
`With an insert having one or more internal grooves to
`accommodate the spring-loaded balls. Apin including such
`a mechanism can be inserted manually, Without tools, and
`removed quickly and easily using a pair of pliers or a special
`extraction tool designed to ?t a hook built into the pin.
`The invention is particularly suited to accomplish quicker
`and easier replacement of teeth used for excavating equip
`ment such as draglines, bucket Wheels, but also is applicable
`to other types of equipment having sacri?cial parts subject
`to high Wear.
`It is an object of this invention, therefore, to provide
`quicker changeovers for sacri?cial parts of machines, espe
`cially digging equipment.
`It is a further object of this invention to provide an
`improved system for attaching replaceable teeth to drag line
`buckets and similar equipment.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is an exploded vieW of a preferred embodiment of
`the tooth assembly of this invention mounted on a conven
`tional tooth horn of a bucket or shovel of an excavating
`apparatus;
`FIG. 2 is a perspective vieW of the tooth assembly
`illustrated in FIG. 1 assembled on the conventional tooth
`horn;
`FIG. 3 is an exploded vieW of the adapter and tooth point
`elements of the tooth assembly illustrated in FIGS. 1 and 2
`in a second preferred embodiment;
`
`1O
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`6,119,378
`
`2
`FIG. 4 is a perspective vieW of an insert element of the
`tooth assembly illustrated in FIGS. 1—3;
`FIG. 5 is a partial sectional vieW of the adapter, tooth
`point and insert elements of the tooth assembly in assembled
`con?guration as illustrated in FIG. 2;
`FIG. 6 is a side vieW of the tooth assembly shoWing the
`locations Where speci?c tolerances are provided according
`to one embodiment of my invention;
`FIG. 7 is a top vieW of the tooth assembly also shoWing
`the locations Where speci?c tolerances are provided accord
`ing to one embodiment of my invention;
`FIG. 8 is a sectional vieW of the improved insert and pin
`using spring-loaded ball bearings; and
`FIG. 9 is a sectional vieW of an alternate embodiment of
`the improved pin utiliZing springs.
`FIG. 10 is a detail shoWing one possible arrangement of
`a bar-type hook recessed into the head of a retaining pin.
`FIG. 11 illustrates an extraction tool that can be used to
`remove the improved retaining pin of this invention.
`
`DETAILED DESCRIPTION
`
`I Will describe the attachment system of my invention
`With particular reference to the attachment of replaceable
`teeth to excavating equipment such as dragline buckets, and
`more particularly to the assembly disclosed in my US. Pat.
`No. 5,337,495 (issued Aug. 16, 1994) and in my US. patent
`application Ser. No. 09/158339, ?led Sep. 21, 1998 (System
`and Method for Improving the Service Life of Replaceable
`Parts Exposed to Shock Loading), the disclosures of Which
`are incorporated by reference herein. Those skilled in the art
`Will understand, hoWever, that my invention also is appli
`cable to other machines using replaceable parts. Examples of
`such machines include doWnhole drills and related tools,
`conveyor belt parts, center Wear shrouds and Wing shrouds
`on dragline buckets, track shoes for tracked vehicles,
`machine gun and artillery breech parts and the like.
`Referring to the draWings and to FIGS. 1 and 2 in
`particular, the tooth assembly of this invention is generally
`illustrated by reference numeral 1 and is mounted on a
`conventional tooth horn 2 of the bucket or shovel of a
`conventional excavator (not illustrated). The tooth assembly
`1 includes a Wedge-shaped adapter 3, ?tted With a removable
`tooth point 15, Which has a contact edge 18 and is mounted
`on the adapter 3 by means of a pair of tooth point retainer
`pins 33, each extending through a tooth point retainer pin
`opening 14 in the tooth point side Wall 17 of the tooth point
`15 and threaded in an insert 41, seated in opposite sides of
`the adapter 3. In a preferred embodiment, the tooth assembly
`1 further includes a transversely-mounted top Wear cap 22
`and bottom Wear cap 36, both of Which are also bolted to the
`adapter 3 by means of side plate bolts 32, respectively. In a
`most preferred embodiment of the invention the adapter 3
`includes a Wedge-shaped adapter base 4 Which tapers from
`a base plate 4a to a nose ridge 12, terminating the adapter
`nose 11. Abase plate lock opening 5 is provided in the base
`plate 4a of the adapter base 4 for receiving a spool 38 and
`a companion Wedge 39 and mounting the adapter 3 on the
`tooth horn 2 in conventional fashion. A pair of transverse,
`vertically-oriented, spaced stabiliZing slots 6 are provided in
`the sides of the adapter base 4, for purposes Which Will be
`hereinafter further described. Spaced, parallel top rib slots 7
`are also provided transversely in the top tapered face of the
`base plate 4a of the adapter base 4 and in a most preferred
`embodiment, the top rib slots 7 are T-shaped, as illustrated
`in the draWings. Similarly, a pair of spaced, T-shaped bottom
`
`Page 7 of 10
`
`

`

`3
`rib slots 8 are provided in the bottom tapered surface or face
`of the adapter base plate 4a in the same relative position as
`the top rib slots 7. It is understood that the top rib slots 7 and
`bottom rib slots 8 may alternatively be shaped in a “dove
`tail”, or alternative locking con?guration, according to the
`knowledge of those skilled in the art.
`As further illustrated in FIG. 1, the top Wear cap 22 and
`bottom Wear cap 36 are designed to slidably mount trans
`versely on the adapter base 4 of the adapter 3. The L-shaped
`top Wear cap 22 and bottom Wear cap 36 are each charac
`teriZed by identical cap plates 23 and corresponding side
`plates 26 and are therefore interchangeable. The cap plate 23
`of the top Wear cap 22 further includes a cap plate opening
`24, Which registers With the base plate lock opening 5
`located in the adapter 3, to provide access to the spool 38 and
`Wedge 39 for readily tensioning the Wedge 39 if necessary,
`as illustrated in FIG. 1. Apair of spaced, T-shaped cap plate
`ribs 25 are transversely located in the bottom surface of the
`cap plate 23 of the top Wear cap 22 and are designed to
`register With the spaced top rib slots 7 provided in the
`adapter 3. Similarly, additional cap plate ribs 25 are provided
`in spaced relationship in the top surface of the cap plate 23
`of the bottom Wear cap 36 for registering With corresponding
`spaced parallel bottom rib slots 8, located in the bottom face
`of the adapter 3, also as illustrated in FIG. 1. A side plate
`retainer pin opening 30 is provided in each of the side plates
`26 of the top Wear cap 22 and the bottom Wear cap 36 for
`receiving the side plate bolts 32, respectively, in order to
`lock the top Wear cap 22 on the top and one side of the
`adapter 3 and the bottom Wear cap 36 on the bottom and
`opposite side of the adapter 3, as illustrated in FIG. 2. As
`further illustrated in FIGS. 1 and 2 of the draWings, the
`adapter 3 is ?tted With an adapter recess 10 on one side to
`facilitate recessing of the side plate 26 of the bottom Wear
`cap 36 and extension of the corresponding cap plate ribs 25,
`located in the bottom surface of the cap plate 23 of the top
`Wear cap 22, into the corresponding side plate slots 28,
`provided in the extending end of the side plate 26 of the
`bottom Wear cap 36. Similarly, the projecting cap plate ribs
`25, located in the cap plate 23 of the bottom Wear cap 36,
`project in registration With the corresponding side plate slots
`28, located in the extending end of the side plate 26 of the
`top Wear cap 22 When the top Wear cap 22 and bottom Wear
`cap 36 are assembled and interlocked on the adapter 3, as
`illustrated in FIG. 3. A side plate recess 29 is provided in the
`side plate 26 of each of the top Wear cap 22 and bottom Wear
`cap 36 and surrounds a corresponding side plate retainer pin
`opening 30, to accommodate the head of the side plate bolts
`32 in countersunk, recessed relationship. Furthermore,
`spaced side plate lugs 31 are provided in the side plate 26 of
`the top Wear cap 22 and bottom Wear cap 36 for registering
`With the corresponding spaced stabiliZing slots 6, located in
`the sides of the adapter 3, respectively. Accordingly, it Will
`be appreciated by those skilled in the art that When the top
`Wear cap 22 and bottom Wear cap 36 are mounted on the
`adapter 3 from opposite sides, With the respective cap plate
`ribs 25 engaging corresponding top rib slots 7 and bottom rib
`slots 8 located in the bevelled top and bottom faces of the
`adapter base 4a, respectively, the top Wear cap 22 and
`bottom Wear cap 36 are interlocked as illustrated in FIGS. 1
`and 2. Furthermore, insertion of the side plate bolts 32
`through the respective side plate retainer pin openings 30 in
`the side plates 26 of the top Wear cap 22 and bottom Wear
`cap 36, respectively, and threading of the side plate bolts 32
`in the respective threaded openings 13 located in the sides of
`the adapter 3, locks the top Wear cap 22 and bottom Wear cap
`36 securely on the adapter 3, With the side plate lugs 31
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`6,119,378
`
`4
`engaging the corresponding stabiliZing slots 6 located in the
`adapter 3. The top Wear cap 22 and bottom Wear cap 36 are
`thus prevented from disengaging the adapter 3 Without
`removing the side plate bolts 32. Moreover, the heads of the
`side plate bolts 32 are securely recessed inside the respective
`side plate recesses 29, provided in the side plates 26, to
`minimiZe the possibility of shearing the side plates retainer
`pins 32 from the tooth assembly 1.
`In another preferred embodiment of the invention each of
`the side plate bolts 32 is provided With a retainer pin
`shoulder 32a located beneath the head thereof. HoWever, in
`a most preferred embodiment of the invention the heads of
`the respective side plate bolts 32 are spaced from the recess
`shoulder 29a of each side plate recess 29. This spacing
`facilitates limited movement of the top Wear cap 22 and
`bottom Wear cap 36 With respect to the adapter 3 as
`described in my US. Pat. No. 5,172,501 and serves as a
`stress-relieving function to minimiZe damage to the tooth
`assembly 1 by operation of the excavation or levelling
`equipment upon Which the tooth assembly 1 is mounted.
`Referring noW to FIGS. 1 and 3—5 of the draWings, the
`tooth point 15 is removably attached to the adapter 3 by
`means of tWo tapered inserts 41, each inserted in a
`correspondingly-shaped insert cavity 47, provided in the
`Wedge-shaped tooth point side Walls 17 of the adapter 3.
`Each insert 41 includes an insert bore 45, extending through
`a tapered, rounded insert body 44 Which terminates in an
`insert shoulder 42, having a straight shoulder edge 43. The
`respective oppositely-disposed insert cavities 47 are tapered
`and shaped to de?ne a cavity shoulder 48, Which engages the
`insert shoulder 42, and a body curvature 49, Which engages
`the insert body 44. Accordingly, the insert cavities 47
`removably receive the inserts 41 and prevent the inserts 41
`from rotating When pressure is applied to the tooth point
`retainer pins 33, Which secure the tooth point 15 on the
`adapter 3. When the preferred retainer pins of FIGS. 8 and
`9 are used, lockWasher 35 is preferably omitted. Optionally,
`When the retainer pins of FIGS. 8 and 9 are used, the insert
`41 may not require an insert shoulder that is shaped to
`prevent rotation.
`Those skilled in the art Will understand that various
`shapes can be used for insert 41, such as square, circular,
`star-shaped and the like.
`Accordingly, referring again to FIGS. 1 and 2, the tooth
`point 15 is designed to mount frontally on the adapter nose
`11 of the adapter 3 by matching the tooth point retainer pin
`openings 14, located in the opposite tooth point side Walls 17
`of the tooth point 15, With the corresponding insert bores 45,
`provided in the inserts 41. Each tooth point retainer pin 33
`is then registered With a corresponding tooth point retainer
`pin opening 14 and the shank of each tooth point retainer pin
`33 is inserted into the corresponding insert bore 45 located
`in the insert 41, to removably secure the tooth point 15 on
`the adapter 3. When the tooth point 15 is so inserted on the
`adapter 3, the tooth point edge 15a is located in close
`proximity to the corresponding edges of the cap plates 23
`and side plates 26 of the top Wear cap 22 and bottom Wear
`cap 36, respectively, as illustrated in FIG. 2. HoWever, a
`Working gap 37 is maintained betWeen the tooth point edge
`15a of the tooth point 15 and the front edges of the top Wear
`cap 22 and bottom Wear cap 36, respectively, to facilitate
`movement of the tooth point 15 and top Wear cap 22, as Well
`as the bottom Wear cap 36, With respect to the adapter 3. As
`illustrated in FIG. 5, since the diameter of the tooth point
`retainer pin opening 14 is smaller than the external dimen
`sions of the inserts 41 at the insert shoulder is 42, the inserts
`41 cannot exit the respective insert cavities 47 through the
`
`Page 8 of 10
`
`

`

`6,119,378
`
`5
`tooth point retainer pin openings 14. However, the inserts 41
`can be easily removed from the insert cavities 47 When the
`teeth are removed from the adapter 3. Accordingly, the tooth
`point 15 is afforded a range of movement on the adapter nose
`11 due to the space betWeen the heads of the tooth point
`retainer pins 33 and the periphery of the tooth point retainer
`pin openings 14, as Well as the Working gap 37, to relieve
`digging stresses.
`It Will be appreciated from a consideration of the draW
`ings that the tooth assembly of this invention exhibits
`multiple favorable structural characteristics not found in
`conventional assemblies. The interlocking relationship
`betWeen the top Wear cap 22 and bottom Wear cap 36, along
`With the transverse, slidable mounting of these structural
`members and the removable mounting of the tooth point 15
`on the adapter 3, facilitate an extremely strong, versatile
`Wear-resistant assembly. Furthermore, recessing of the
`respective side plate bolts 32 and tooth point retainer pins
`33, as Well as the side plates 26 of the top Wear cap 22 and
`the bottom Wear cap 36 provided in opposite sides of the
`adapter 3, facilitate excavation and levelling of all types of
`material Without fear of shearing the respective side plate
`bolts 32 and tooth point retainer pins 33. Moreover, use and
`replacement of the top Wear cap 22, bottom Wear cap 36 and
`tooth point 15 independently or in concert, is quickly and
`easily facilitated in an optimum manner by simply removing
`the side plate bolts 32 and tooth point retainer pins 33,
`sliding the top Wear cap 22, bottom Wear cap 36 and tooth
`point 15 from the adapter 3 and replacing these members by
`reversing this procedure. Shock and impact resistance of the
`tooth assembly 1 is facilitated by mounting the top Wear cap
`22 and bottom Wear cap 36 and tooth point 15 in a non-rigid,
`but secure relationship on the adapter 3 to facilitate a
`selected minimum movement of the top Wear cap 22, bottom
`Wear cap 36 and tooth point 15 With respect to the adapter
`3 during operation. Use of the inserts 41 to mount the tooth
`point 15 on the adapter 3 facilitates quick and easy removal
`and replacement of the tooth point 15 Without risk of
`cross-threading a tooth point bolt directly into tapped holes
`provided in the adapter 3. Such tapped holes are subject to
`various types of damage and the inserts 41 are capable of
`easy replacement to avoid this problem. A tooth assembly 1
`is mounted on each tooth horn 2 of a conventional bucket or
`shovel of a conventional excavating apparatus in conven
`tional manner, utiliZing the spool 38 and Wedge 39, accord
`ing to the knoWledge of those skilled in the art. It Will be
`appreciated that alternative means for mounting the tooth
`assembly 1 to the tooth horn of such equipment may also be
`implemented Without departing from the spirit and scope of
`the invention as embodied herein.
`FIG. 6 and FIG. 7 illustrate the speci?c tolerances of my
`invention. FIG. 6 shoWs a preferred embodiment of my
`invention as applied to a replaceable tooth point 15 for a
`dragline bucket. In the side vieW of FIG. 6, the removable
`tooth point 15 is shoWn attached to the Wedge-shaped
`adapter 3, held loosely in place by insert 41. The approxi
`mate direction of the heaviest shock load is shoWn at
`reference numeral 100. As shoWn in the folloWing examples,
`I have found that providing the folloWing clearances
`betWeen the sacri?cial part (the removable tooth point 15, in
`this example) and the adapter 3 upon Which it is mounted
`Will effectively and surprisingly increase the life of the
`sacri?cial part:
`HoriZontal clearance at reference numeral 101 in approxi
`mate direction of shock: about Vs inch to about 1A inch.
`Vertical clearance at reference numeral 102 normal to
`approximate direction of shock: about 1/32 inch to about
`3/16 inch; preferably about 1/16 inch to about Vs inch.
`
`10
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`6
`HoriZontal clearance at reference numeral 103 normal to
`approximate direction of shock: about 1/32 inch to about
`1/16 inch.
`I ?nd that if larger clearances are used the teeth Will tend to
`move forWard and contact the bolts, causing failure by
`bending or fracture; Whereas if smaller clearances are used
`there Will be interference from the castings, notably betWeen
`the adapter 3 and the sacri?cial part 15.
`FIG. 8 illustrates a preferred embodiment of my invention
`in Which the tooth point retainer pin 202 is not threaded, but
`instead is ?tted With a cavity 205 containing at least one
`spring-loaded ball bearing 203 and a spring mechanism 204
`Which urges the ball bearing 203 radially outWardly as far as
`permitted by the hole 206 in the shank of the insert pin 202.
`The corresponding insert 200 includes an internal slot or
`depression 201 suitable for accommodating the one or more
`ball bearings 203. When the retainer pin 202 is inserted into
`the cavity of the insert 200, the ball bearings 206 retract until
`they reach the internal slot 201, at Which point the spring
`mechanism 206 forces the ball bearings 203 radially out
`Ward into the slot 201, securing the retainer pin 202 in the
`insert 200. This operation preferably is accomplished manu
`ally Without need for tools. To remove the retainer pin 202,
`a pair of pliers may be used, or if the retainer pin 202 is
`designed to be ?ush or recessed, an extractor tool (not
`shoWn) suitable for engaging a hook 207 on retainer pin 202
`may be used to remove the retainer pin 202. Preferably, hook
`207 is arranged as shoWn in FIG. 10, With the hook formed
`as a bar recessed in a cavity 226 in the head of the retaining
`pin to protect it from dirt and Wear. FIG. 11 shoWs an
`extraction tool 220 comprising a shaft 223 on Which a
`sliding Weight 221 moves longitudinally. The distal end of
`the shaft includes a recess 224 suitable for engaging the
`hook or bar 207 that is recessed into the retaining pin shoWn
`in FIG. 10. A stop 222 near the proximal end of the
`extraction tool permits the sliding Weight to act as a slide
`hammer to dislodge retaining pin 202. Optionally, the proxi
`mal end 225 of the extraction tool can be pointed so that it
`can be used to clean out the cavity 226 before engaging the
`bar 207 With the recess 224 near the distal end of the shaft
`of the extraction tool.
`In any event, tooth retention is achieved Without need for
`threading and unthreading a bolt.
`FIG. 9 illustrates an alternative embodiment, in Which
`instead of ball bearings, one or more springs 213 set into
`cavities 214 are used to retain the retainer pin 212 in the
`insert 210 by engaging slots 211.
`It Will be understood that the arrangements of springs or
`ball bearings and slots illustrated in FIGS. 9 and 10 can be
`reversed if desired, so that the spring or springs are placed
`in the adapter and the mating slot is in the retainer pin.
`In addition, the insert can be eliminated altogether by
`machining an aperture and slot directly into the adapter nose
`11 in the insert cavity 49.
`
`EXAMPLES
`In a test comparing dragline bucket teeth attached to a 90
`cubic yard dragline bucket according to my invention With
`conventional, rigidly-attached dragline bucket teeth, the
`teeth attached according to my invention exhibited an aver
`age life of approximately 161 hours compared to 79 hours
`for the conventionally-attached teeth. The adapter used With
`the non-rigid attachment system of my invention exhibited
`an average life of approximately 1655 hours compared to
`1113 hours for the adapter using conventional, rigid attach
`ment to the teeth.
`In another test at a Phelps-Dodge mine, the rate of tooth
`Wear using my non-rigid attachment system on a dragline
`
`Page 9 of 10
`
`

`

`6,119,378
`
`7
`bucket Was approximately 0.75 inches per 24 hour period,
`approximately half the rate of Wear for conventional, rigid
`attachment of the teeth.
`Those skilled in the art Will appreciate that increasing the
`life of the sacri?cial parts not only saves money for replace
`ment parts themselves, but also reduces maintenance doWn
`time and labor costs for parts replacement.
`I claim:
`1. An improved attachment system for sacri?cial machine
`parts that are subject to shock loading and mountable to an
`adapter, comprising:
`a. a replaceable sacri?cial machine part de?ning a cavity
`and having an outer bore extending into said cavity;
`b. an adapter mountable to a machine and having an insert
`Which is insertable into said cavity and having an
`internal bore, said internal bore positioned to aligned
`With said outer bore;
`c. a slot in said internal bore of said insert;
`d. a retaining pin insertable through said outer bore and
`into said internal bore for mating said replaceable
`machine part to said adapter;
`e. at least one spring-loaded ball bearing situated inside
`said retaining pin and adapted to engage said slot in
`
`5
`
`15
`
`8
`said bore of said insert When said retaining pin is
`inserted into said adapter.
`2. An improved attachment system for sacri?cial machine
`parts that are subject to shock loading and mountable to an
`adapter, comprising:
`a replaceable sacri?cial machine part de?ning a cavity
`and having a plurality of opposingly located outer bores
`extending into said cavity;
`an adapter mountable to a machine and having an insert
`Which is insertable into said cavity and having a
`plurality of opposingly located internal bores, each of
`said internal bores positioned to aligned With a corre
`sponding outer bore;
`a slot in each of said internal bores of said insert;
`retaining pins insertable through said outer bores and into
`said internal bores for mating said replaceable machine
`part to said adapter; and
`at least one spring-loaded ball bearing situated inside each
`retaining pin and adapted to engage a corresponding
`slot in said bores of said insert When said retaining pins
`are inserted into said adapter.
`
`*
`
`*
`
`*
`
`*
`
`*
`
`Page 10 of 10
`
`