`(10) Patent No.:
`Us 7,914,226 132
`Miller
`(45) Date of Patent:
`Mar. 29, 2011
`
`US007914226B2
`
`(54) NON-REMOVABLE SAFETY PIN
`
`(75)
`
`Inventor: Gary Miller, Tyne & Wear (GB)
`
`(73) Assignee: Miller UK Limited, Northumberland
`(GB)
`
`*
`
`Notice:
`
`J
`y
`Sub'ect to an disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 538 days.
`
`(21) Appl.No.: 11/349,491
`
`(22)
`
`Filed:
`
`Feb. 7, 2006
`
`(65)
`
`(30)
`
`Prior Publication Data
`
`US 2007/0039213 A1
`
`Feb. 22, 2007
`
`Foreign Application Priority Data
`
`Aug. 17, 2005
`
`(GB) ...................................... 3022197
`
`(51)
`
`Int. Cl.
`325G 3/18
`
`(2006.01)
`(2006.01)
`F16B 21/00
`(2006.01)
`F16D 1/00
`(52) US. Cl.
`.......... 403/324; 403/154; 403/316; 37/468;
`292/150
`
`(58) Field of Classification Search .................. 292/150,
`292/155, 300, 302; 403/150, 154, 155, 157,
`403/315, 316, 319, 324; 411/351, 417; 37/355,
`37/356, 468
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`166,379 A *
`355,980 A *
`566,130 A *
`1,376,945 A *
`
`8/1875 Hipkins et a1.
`. 238/252
`
`1/1887 Dimon ......
`278/96
`
`. 411/351
`8/1896 Bowers .....
`5/1921 Kristofek ........................ 40/121
`
`8/1945 Martin .......................... 411/347
`2,382,166 A *
`3/1952 Lauenstein .
`267/154
`2,588,018 A *
`3,223,201 A * 12/1965 Waner .............. 188/67
`3,869,877 A *
`3/1975 Brahler
`..... 464/97
`3,875,360 A *
`4/1975 Rys ..........
`200/400
`4,030,694 A *
`6/1977 Schimmel
`249/196
`4,337,614 A *
`7/1982 Briscoe ...................... 59/86
`5,630,673 A *
`5/1997 Krzywanos et a1.
`403/158
`6,168,342 B1*
`1/2001 Wu ............................... 403/119
`6,308,442 B1
`10/2001 Naka et a1.
`6,309,131 B1* 10/2001 Dawson .......................... 403/79
`6,309,311 B1* 10/2001 Lu ...............
`473/332
`6,312,212 B1* 11/2001 Burlew, Jr.
`..
`414/723
`6,350,079 B1*
`2/2002 Williams .............. 403/326
`6,379,075 B1 *
`4/2002 Shamblin et a1.
`.......... 403/322.1
`6,431,785 B1
`8/2002 Melander
`6,537,006 B1*
`3/2003 Clark .............................. 411/82
`6,877,259 B2 *
`4/2005 Nishimura et a1.
`............. 37/468
`2004/0060210 A1
`4/2004 Nishimura et a1.
`
`
`
`
`
`GB
`GB
`GB
`GB
`
`FOREIGN PATENT DOCUMENTS
`0420152.1
`2/1933
`357748 A
`8/1981
`2256631 A
`12/1992
`2335907 A
`5/1999
`
`* cited by examiner
`
`Primary Examiner 7 Daniel P Stodola
`Assistant Examiner 7 Nahid Amiri
`
`(74) Attorney, Agent, or Firm 7 Stephen B. Salai, Esq.;
`Michael J. Didas, Esq.; Harter Secrest & Emery LLP
`
`(57)
`
`ABSTRACT
`
`A non-removable safety pin (20) for an excavator coupler for
`securing a latching hook thereof. The safety pin (20) com-
`prises a head (26), a shaft (24), a distal end (22) and a longi-
`tudinal axis starting at the head (2 6), extending along the shaft
`(24) and terminating at the distal end (22), wherein either or
`both ofthe shaft (24) and the distal end (22) are keyed so as to
`have an element thereon that extends relative to a side of the
`
`shaft. The element prevents removal of the safety pin from a
`hole (36) in which the safety pin (20) is inserted.
`
`12 Claims, 5 Drawing Sheets
`
`
`
`Page 1 of 11
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`CATERPILLAR EXHIBIT 1001
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`Page 1 of 11
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`CATERPILLAR EXHIBIT 1001
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`US. Patent
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`Mar. 29, 2011
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`Sheet 1 015
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`US 7,914,226 132
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`US. Patent
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`Mar. 29, 2011
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`US 7,914,226 132
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`US. Patent
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`Mar. 29, 2011
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`Sheet 3 of5
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`US 7,914,226 B2
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`US. Patent
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`Sheet 4 015
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`US 7,914,226 132
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`Page 5 of 11
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`US. Patent
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`Sheet 5 of5
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`US 7,914,226 B2
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`Page 6 of 11
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`1
`NON-REMOVABLE SAFETY PIN
`
`RELATED APPLICATION
`
`US 7,914,226 B2
`
`2
`
`This application is related to UK. Design Patent Applica-
`tion GB3022197, filed Aug. 17, 2005.
`
`FIELD OF INVENTION
`
`The present invention relates to a non-removable safety
`pin, for example for use to secure the engagement ofpivoting
`or sliding latching hooks, or other moving elements, in a
`bucket or accessory coupler for an excavator. Such couplers
`may be for coupling a bucket, or some other accessory, to an
`excavator arm of an excavator.
`
`10
`
`15
`
`BACKGROUND
`
`It is well known in the art of excavators to provide a coupler
`between an end of an excavator arm of the excavator and an
`
`20
`
`accessory for that excavator, such as digging buckets for that
`excavator. Couplers are generally mounted to the arm of the
`excavator with coupler pins. Then, for coupling a bucket
`thereto, at the bottom of the coupler, a fixed pair of hooks and
`either a pair pivoting latching hooks or sliding latching hooks
`is provided. The hooks engage bucket (or accessory) pins,
`which are generally provided at the top of the bucket (acces-
`sory).
`The pivoting or sliding latching hooks are moveable to
`allow the coupler to both secure and release an accessory to
`and from the arm of the excavator mechanically, e.g. at the
`control of a button, using hydraulics or a screw-drive. Gen-
`erally, however, the hook will be hydraulically actuateable
`from within the cab of the excavator for remotely securing
`and releasing the accessory.
`It has become increasingly common to provide a safety pin
`for engaging behind the movable latching hooks (when they
`are in their latched position), by passing it through the side
`plates ofthe coupler, to prevent the hooks from moving back-
`wards, i.e. away from the latched position, in the event of a
`hydraulic failure. Indeed, this safety feature has become man-
`datory in some countries. However, because the safety pin has
`to be inserted manually, in practice it is found that many
`excavator operators either forget to use it or simply refuse to
`use it. This presents a significant health and safety risk both to
`the operator and to those around the excavator.
`
`BRIEF SUMMARY OF INVENTION
`
`The present invention, therefore, seeks to provide a safety
`pin that will help to stop such behaviour, i.e. to prevent opera-
`tors from not using a safety pin.
`The present invention provides a safety pin comprising a
`head, a shaft, a distal end and a longitudinal axis starting at the
`head, extending along the shaft and terminating at the distal
`end, wherein either or both of the shaft and the distal end are
`keyed so as to have an element thereon that extends outward
`relative to a side of the shaft.
`
`Preferably the element extends in a direction that is gener-
`ally perpendicular to the longitudinal axis of the safety pin.
`Preferably the element extends radially outward from the
`rest of the shaft and the distal end.
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`Preferably the head extends radially outward from the side
`of the shaft. Preferably it extends by a similar amount as the
`element.
`
`65
`
`The element may be a complete ring of material, or a
`substantially complete ring of material.
`
`Page 7 of 11
`
`There may be more than one element.
`The element may be formed by stamping the distal end to
`flatten and widen it.
`
`The distal end may be integral with the shaft.
`The distal end may be a separately formed component
`attached to the end of the shaft.
`
`Preferably the shaft is substantially cylindrical. However, it
`might not be fully cylindrical. For example, it may have one,
`two, three or more flat sides or faces or it may be semi-
`cylindrical, i.e. having a semi-circular cross section.
`If the shaft has one or more flat sides or faces, preferably
`the or each flat side or face extends longitudinally along
`substantially the whole length of the shaft.
`Preferably the shaft has more than one side. Preferably
`there are two or more sides that are positioned at different
`radial distances away from the longitudinal axis of the safety
`pin. This allows the pin to be rotated, in use, to provide
`alternative safety positions. For example, with a coupler for
`an excavator, not all manufacturers provide the same size
`bucket (or accessory) pins or the same centre-to-centre pin
`spacings (collectively, multiple pin spacings). Therefore,
`once the coupler’ s hooks have engaged the pins, the safety pin
`can be fitted in a most appropriate orientation by rotating the
`safety pin to face the most appropriately distanced side
`towards the latching hook. This feature, therefore, provides a
`capability for managing multiple pin spacings.
`The distal end of the safety pin may be substantially cylin-
`drical. However, it may have steps therein, and/or perhaps flat
`sides or faces.
`
`The distal end of the safety pin preferably has a hole
`therein. The hole preferably extends transversely through the
`safety pin for receiving a lynch pin or R-clip for locking the
`safety pin in an inserted position, as known in the art of safety
`pins.
`Preferably the distal tip of the distal end ofthe safety pin is
`tapered to assist with the insertion ofthe safety pin into holes.
`Preferably the key is in the form of a shoulder between the
`distal tip of the safety pin and the shaft. Preferably the shoul-
`der is at the juncture between the distal end and the shaft.
`The keyed element provides the safety pin with the means
`for necessitating at least one of the following:
`the correct orientation of the safety pin for removal from a
`hole in which it has been inserted;
`the deformation of or the alteration of the size or shape of
`the hole for removing the safety pin from the hole;
`the deformation ofthe safety pin, the shaft, the distal end or
`the element for removing the safety pin from the hole; or
`the alteration of the shape or form of the safety pin, for
`example by disassembly or breakage of the safety pin, for
`removing the safety pin from the hole.
`Preferably the element extends radially outward beyond all
`of the shaft’s circumferential surface.
`
`The element may be rigidly fixed in its position. Altema-
`tively it may be retractable, rotatable or otherwise moveable
`or deformable from the position in which it blocks the safety
`pin’s removal from a hole.
`Preferably the head comprises a flange for assisting in
`gripping of the safety pin for helping in the retraction of the
`safety pin from a safe or inserted position to a non-safe or
`retracted position.
`Preferably the head is non circular, or it provides a grip by
`some other means, to assist with turning of the pin about its
`longitudinal axis.
`The present invention also provides a hole for receiving a
`safety pin, for example in a coupler for an excavator, in
`combination with a safety pin as described above.
`
`Page 7 of 11
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`
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`US 7,914,226 B2
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`3
`Preferably the hole for receiving the safety pin is sized to
`allow the shaft (and/or distal end) to slide through the hole up
`to the point where the projecting or outwardly extending
`element is. Therefore, the safety pin will not pass all the way
`through the hole.
`Preferably the shape or size ofthe hole is defined, at least in
`part, by a plate.
`Preferably the plate is removable. Preferably, by removing
`the plate, the size of the hole is altered. Preferably the altered
`size allows the shaft, the distal end and projecting or out-
`wardly extending element to pass through the hole. This
`allows the safety pin to be removed so that it becomes a
`serviceable part.
`Preferably the plate is screwed or bolted over a portion of
`the hole.
`
`Preferably the plate covers a sector of the hole.
`The hole is preferably in a side plate of a coupler for an
`excavator arm.
`
`Preferably there is also an opposing hole, which may be in
`axial alignment with the first hole. Preferably the opposing
`hole is in an opposite side plate of a coupler. Preferably the
`opposing hole is sized or shaped to receive the distal end of
`the safety pin.
`Preferably the opposing hole is a through hole. Preferably
`the safety pin, in its inserted position, extends out beyond the
`far side of the opposing hole.
`Preferably the safety pin is of a length to pass through the
`first hole and to extend to the opposing hole to allow a safety
`pin securement device to secure the safety pin in its safe or
`inserted position.
`Preferably a safety pin securement device is provided.
`Preferably the safety pin securement device comprises a hole
`in the distal end and a lynch pin or R-clip for locking the
`safety pin in an inserted position, as known in the art of safety
`pins.
`The safety pin may comprise a substantially semi-cylindri-
`cal shaft with a substantially cylindrical distal end having a
`substantially semi-circular shaped shoulder therebetween.
`Preferably the hole is then a substantially round hole that
`slidably receives the safety pin, and there is a removable
`locking plate provided over the hole to close a sector of the
`substantially round hole for slidably locking the safety pin in
`the hole. Preferably the sector is substantially a semi-circle,
`corresponding to, or slightly less full or smaller than, the
`shoulder. In this manner the safety pin cannot be removed
`from the hole without removing the plate. The shoulder pro-
`vides the keyed element that extends outward relative to the
`flat side of the semi-cylindrical shaft.
`In an alternative embodiment, the safety pin comprises a
`cylindrical shaft and a keyed distal end, wherein the keyed
`distal end comprises a flattened portion having a wider width
`than the diameter of the shaft, and the head comprises a
`removable element having a larger size than the diameter of
`the shaft. In use, the pin is inserted first through an opposing
`hole without the head attached thereto by inserting the shaft
`through the hole, and then through the first hole, and once in
`place, the head is then attached to the shaft to lock the safety
`pin in the hole. Only by removing the head will the safety pin
`then be removable from the holes for servicing.
`The present invention also provides a hole for receiving a
`safety pin, for example in a coupler for an excavator, in
`combination with a safety pin comprising a head, a shaft, a
`distal end and a longitudinal axis starting at the head, extend-
`ing along the shaft and terminating at the distal end, wherein
`either or both of the shaft and the distal end are keyed so as to
`have an element thereon that extends inward relative to a side
`
`of the shaft, wherein the hole comprises means for engaging
`
`10
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`4
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`into the element for preventing removal ofthe safety pin from
`the hole if the safety pin is retracted or otherwise put into a
`position in which the element aligns with the means for
`engaging.
`Preferably the means for engaging is a sprung element.
`Preferably the element has a ramped edge to allow the
`safety pin to be reinserted from the retracted position, the
`means for engaging riding out ofthe element over the ramped
`edge.
`Preferably the means for engaging is part of a removable
`plate.
`The present invention also provides a coupler having a
`pivoting or sliding latching hook and at least one hole for
`receiving a safety pin for sliding behind the hook once the
`hook has been engaged with a bucket pin or an accessory pin,
`the coupler additionally comprising a safety pin, wherein the
`safety pin or the hole in combination with the safety pin is as
`defined above.
`
`The coupler, at the hole for receiving the safety pin, may
`comprise a locking plate. This locking plate may be welded in
`place to permanently lock the safety pin into the coupler.
`Alternatively, the locking plate may be removably fastened to
`the coupler at the hole, for example, by two bolts. This allows
`the locking plate to be removed for removal of the safety pin,
`for example for servicing purposes.
`With the present invention, because the safety pin cannot
`be easily removed from its hole, the chances of an operator
`removing and then losing the pin are substantially reduced.
`Further, the pin, when retracted to a non-safe position, is
`likely to be visible to the operator to remind him to re-insert
`it into the safety position. In this regard, the safety pin may
`advantageously be provided in a bright colour to help make it
`stand out.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The present invention will now be described by way of
`example only with reference to the accompanying drawings
`in which:
`
`FIG. 1 shows a safety pin of the first embodiment fitted to
`a coupler;
`FIG. 2 is a perspective view of the safety pin of FIG. 1;
`FIG. 3 is a perspective view of an alternative embodiment
`of safety pin;
`FIG. 4 is a perspective view of a head of the safety pin of
`FIG. 3 engaged against a boss of a coupler;
`FIG. 5 shows the pin in the process of being removed;
`FIG. 6 shows a cross section through the coupler of the
`holes for receiving the pin of FIG. 3;
`FIG. 7 shows a further embodiment of safety pin resting
`against latching hooks of a coupler;
`FIG. 8 shows the safety pin in its non-safe or retracted
`positionithe latching hooks can be disengaged; and
`FIG. 9 shows the safety pin in a rotated position.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`Referring first to FIG. 1, there is shown a coupler 10 having
`a pair of rear hooks 12 (one shown), a pair of front pin
`receiving slots 14, a pair of pivoting latching hooks (not
`shown, but pivotal about hook pivot pin 16), two pairs of
`coupler pin receiving holes 18 (one pair shown) and a safety
`pin 20a.
`In use, coupler pins (not shown) will be used to mount the
`coupler 10 to an end of an excavator arm of an excavator (not
`shown). The safety pin 2011 would then be pulled out of its
`inserted position into a non-safe position (see, for example,
`
`Page 8 of 11
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`Page 8 of 11
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`US 7,914,226 B2
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`5
`FIGS. 5, 8 or 9). Then, the rear hooks 12 and the latching
`hooks would be used to attach the coupler 10 to an accessory,
`such as a bucket (not shown), as known in the art. See, for
`example, FIGS. 1 and 2 of GB2359062. In the prior art,
`however, the safety pin would be fully removed.
`Once the latching hook has been advanced into its engaged
`or latched position, the safety pin 2011 would then be rein-
`serted into the safe position to prevent the latching hook from
`being able to retract or disengage from the latched position.
`To release the bucket, the safety pin 20a is again retracted
`to its non-safe position and the latching hook is retracted to a
`non-latched position. Then the rear hooks 12 can be disen-
`gaged.
`Referring now to FIG. 2, the safety pin 20a comprises a
`distal end 2211, a shaft 24a, and a head 26a. These are linearly
`arranged along a longitudinal axis of the safety pin 20a. The
`distal end 22a is generally cylindrical. The shaft 24a is gen-
`erally semi-cylindrical. The head 26a comprises a flange
`extending radially outward relative to the shaft.
`A transverse hole 30 is provided in the distal end. It is sized
`to receive a lynch pin or an R-clip (not shown).
`The juncture between the cylindrical distal end 22a and the
`shaft 2411 defines a semi-circular shoulder 3211. It extends
`
`perpendicular to the longitudinal axis of the safety pin 20a.
`The head 2611, the shaft 24a and the distal end 22a are all
`integrally formed as a single piece.
`The semi-circular shaft 24a has a flat surface 34. In use, the
`flat surface 34 will usually face the rear side of the latching
`hook.
`
`The safety pin can be cast into the above shape. It might
`alternatively be ground into that shape from a conventional
`safety pin.
`Referring again to FIG. 1, the safety pin 20a is fitted into a
`hole 36 in a side plate 38 of the coupler 10 (the side plates of
`couplers are not necessarily flat, and are not necessarily
`formed from a plateisome couplers are cast and then
`ground/milled to a final shape).
`The hole 36 is sized for receiving the shaft 24a ofthe safety
`pin 20 with a sliding fit. However, the head 26a of the safety
`pin 20a is too big to pass through the hole 36.
`An opposing hole (not shown) in the opposite side plate is
`also provided. The opposing hole is sized for receiving the
`distal end 2211 of the safety pin 2011 with a sliding fit.
`Upon inserting the safety pin 2011 into its safe position, the
`distal end 2211 of the safety pin will extend into the hole and
`through it. The lynch pin or R-clip (not shown) may then be
`fitted through the transverse hole 30 for securing the safety
`pin in that position.
`The distal tip 40 of the distal end 22a of the safety pin 20a
`is chamfered to assist with the insertion of the safety pin 20a
`through the holes (36).
`The hole 36 is a round hole. However, a locking plate 42 is
`fastened to the coupler 10 over a sector of the hole 36 by two
`bolts 44. By covering the sector of the hole 36, the semi-
`cylindrical shaft 24a will fit in the hole in only one orienta-
`tion. This ensures that the flat surface ofthe shaft rests against
`the rear side of the latching hook.
`The locking plate also serves a second, more significant
`purpose. It prevents the safety pin 20a from being removable
`from the hole 36. Upon retracting the safety pin 20a to the
`non-safe position, the shoulder 32 will engage the back of the
`locking plate, thereby resisting further outward movement of
`the safety pin 20a. However, since the locking plate 42 is only
`bolted to the coupler, the locking plate 42 can be removed to
`allow the safety pin 20a to be removed, for example for
`servicing.
`
`5
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`6
`The length ofthe distal end can also be made to be the same
`as the thickness of the side plate of the coupler at the hole. In
`this manner, the safety pin 20a, in its retracted, or non-safe,
`position, will be retracted sufficiently to not extend into the
`internal space of the coupler. It will therefore not be able to
`interfere with any of the operational parts of the coupler 10.
`With the present invention, the safety pin remains attached
`to the coupler frame during accessory release, held secure by
`the locking plate. The present invention therefore eliminates
`the danger of safety pin loss.
`Referring now to FIGS. 3, 4 and 5, a second embodiment of
`safety pin 20b is shown. It also comprises a head 26b, a shaft
`24b and a distal end 22b. Further, the distal end has a trans-
`verse hole 30 there through for a lynch pin or R-clip. How-
`ever, in this embodiment, the head 26b is removable from the
`shaft 24b
`
`The head 26b is a bolt 46 with an integral washer 48 and an
`integral shaft (not shown) that is screwed into the shaft 24b of
`the safety pin 20b.
`The distal end 22b is integrally formed as a single piece
`with the shaft 24b. It has the transverse hole 30 drilled there-
`
`through. However, the distal end 22b, instead of being cylin-
`drical, is now flattened. For example, it may be stamped to
`form two flat faces and two transversely extending sides. The
`two transversely extending sides extend radially outward
`relative to the shaft 24b.
`
`The shaft is cylindrical along its length.
`As shown in FIGS. 4 and 5, and similar to the first embodi-
`ment, the safety pin 20b is provided in a coupler 10 and it
`extends between two holes 36 in the side plates 38 of the
`coupler. However, the hole 36 is provided with a boss 54. The
`boss 54 provides a flat surface for the washer 48 to rest
`against. Further, it makes the side plate’s thickness T thicker
`at that point by the depth D of the boss 54, as shown in FIG.
`6. The additional thickness provides for a larger space for
`housing the distal end 22b of the safety pin 20b upon retract-
`ing the safety pin 20b into the non-safe position. Therefore, as
`before, prior to accessory release (or coupling), the safety pin
`is pulled from the coupler until it is retracted into the designed
`housing within the coupler frame to avoid any interference
`with the internal operating components of the coupler.
`The housing 58 comprises a mortise that is centred over the
`first hole 36. It is larger in width than the holeithe housing
`receives the distal end 22b, whereas the hole 36 is sized to
`receive the shaft 24b, which is smaller than the distal end 22b.
`In the retracted position, the shoulder 32 of the distal end
`22b of the safety pin 20b bears against a shoulder 60 between
`the housing 58 and the hole 36. This prevents the removal of
`the safety pin.
`The mortise may be round or shaped to accommodate the
`distal end in just one or more specific orientation (e.g. rect-
`angular, star shaped, or otherwise).
`FIG. 6 also shows the opposing hole 56. It has a similar
`width W to the housing 58 since it also is adapted to accom-
`modate the distal end 22b of the safety pin 20b, but instead
`when the safety pin 20b has been inserted into its safe posi-
`tion. It also can be round or shaped to accommodate the distal
`end in just one or more specific orientation. This is useful, for
`example, since by using different rotational orientations and
`a non-concentric shaft or by having flat sides on the shaft that
`have different radial displacements relative to the longitudi-
`nal axis through the head and the distal end (as described
`later), different locking positions for the latching hook can be
`secured by the safety pin (multiple pin spacings).
`
`Page 9 of 11
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`Page 9 of 11
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`US 7,914,226 B2
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`7
`Referring now to FIGS. 7, 8 and 9, a final embodiment is
`shown. This cutaway perspective view generally omits the
`side plate 38 by making it transparent so that the latching
`hooks 62 can be seen.
`
`The latching hooks 62 are moveable by a hydraulic piston
`64.As shown, they engage a bucket pin 66. It is in this position
`that a safety pin 200 secures the latching hook.
`The safety pin 200 in this embodiment again comprises a
`distal end 220, a shaft 240 and a head 260
`The head 260 comprises a flange 28 extending beyond the
`surface of the shaft 240.
`
`The distal end 220 comprises a transverse hole 30 for a
`lynch pin or R-clip, which hole extends between two flat faces
`50. The distal end, however, also has a stepped down portion
`80 with a smaller radius than the maximum radius ofthe shaft
`
`and the rest 82 of the distal end 220 (which two radiuses may
`be the same). This stepped down portion 80, as shown in FIG.
`8, allows the safety pin 200 to rotate when withdrawn to the
`point at which the locking plate 42 aligns with the stepped
`down portion 80.
`In this embodiment, the shaft 240 has three flat surfaces 68,
`70, 72 and a fourth, rounded surface 74. The shaft has a
`substantially constant cross section along its full length. The
`interfaces between the adjacent surfaces may be rounded.
`They fall on the same inscribed circle as the rounded surface
`74. In this manner, the shaft will readily slide in the two holes
`36, 56 in the side platesisee the distal part of the safety pin
`in FIG. 7, where the interfaces touch the sides ofthe opposing
`hole 56. The rounded surface does as well.
`
`A locking plate 42, as in the first embodiment, is provided.
`It also is attached by two bolts 44. It also covers a sector ofthe
`first hole 36. The sector, however, is less full. In use, i.e. when
`the safety pin 200 is inserted into the safe position, a side 78
`ofthe locking plate 42 rests against one ofthe flat surfaces 68,
`70, 72 of the shaft 240.
`As shown in FIG. 9, the first flat surface has a first width
`W1. As shown in FIG. 7, the second flat surface 70 has a
`second width W2. As a result, the centreline of those flat
`surfaces 68, 70 are radially displaced from the central longi-
`tudinal axis of the safety pin (which corresponds with the
`central axis of the holes and through the head and the distal
`end 220 of the safety pin), by different amounts. Further, the
`round surface is even further radially displaced than those
`surfaces. Therefore, by selectively orientating the safety pin
`while the pin is withdrawn to a non-safe position, which is
`possible in view of the stepped down portion 80, different
`securement positions for the latching hook can be achieved.
`This allows for multiple pin spacings to be catered for.
`The safety pin is secured in its rotational orientation by the
`locking plate 42. In fact, the safety pin of this embodiment
`will only insert in three orientations, i.e. when a flat surface
`68,70, 72 faces the locking plate 42. In the orientation of FIG.
`9, however, the distal end ofthe round surface 74 fouls against
`the locking plate 42, thereby preventing reinsertion of the
`safety pin 42. Similarly, if the safety pin 200 was to be ori-
`ented such that one ofthe two interfaces 76 was to point at the
`locking plate 42, the interface 76 instead would foul the
`locking plate 42. Therefore, the safety pin ofthis embodiment
`will only insert in three orientations, each one providing for a
`different bucket pin spacing.
`The distal portion of the distal end prevents full removal of
`the safety pin since it has the same radius as the round surface.
`Although a particular application for the safety pins has
`been described, it is anticipated that the safety pins of the
`present invention may also be used in other applications. For
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`8
`example, they may be used as the bucket pins, the accessory
`pins or as coupler pins, or for agricultural equipment needing
`safety pins.
`The safety pins of the present invention may be referred to
`as non-removable safety pins since they cannot easily be
`removed.
`
`The present invention has been described above purely by
`way ofexample. It should be noted that modifications in detail
`may be made within the scope of the invention.
`The invention claimed is:
`
`1. A system for retaining engagement of first and second
`elements within a coupler, the system comprising:
`a coupler having a sidewall and an aperture formed there-
`through;
`a safety pin insertable into an aperture formed through a
`sidewall ofthe coupler, the safety pin comprising a head,
`a shaft depending from the head along a longitudinal
`axis, a distal end of the shaft opposite the head, and an
`element that extends radially outwardly from a portion
`of the shaft, the shaft, the distal end of the shaft and the
`element disposed in the aperture of the coupler; and
`a removable plate fixed to the sidewall of the coupler
`occluding a portion of the aperture corresponding sub-
`stantially in size and shape with the element ofthe safety
`pin to prevent passage of the distal end of the safety pin
`through the aperture, wherein when the removable plate
`is fixed to the sidewall of the coupler the portion of the
`aperture not occluded by the removable plate is sized to
`allow passage of the shaft through the aperture.
`2. The system of claim 1, wherein the element is formed by
`stamping the distal end to flatten and widen it.
`3. The system of claim 1, wherein the distal end is integral
`with the shaft.
`
`4. The system of claim 1, wherein the shaft is substantially
`cylindrical.
`5. The system of claim 1, wherein the shaft has one or more
`flat sides.
`
`6. A system for retaining engagement of first and second
`elements within a coupler, the system comprising:
`a coupler having a sidewall and an aperture formed there-
`through, the aperture having an aperture axis;
`a safety pin comprising a head, a shaft depending from the
`head along a longitudinal axis, a distal end of the shaft
`opposite the head, and an element that extends radially
`outwardly from a portion ofthe shaft, the shaft, the distal
`end of the shaft and the element disposed in the aperture
`of the coupler with the longitudinal axis substantially
`aligned with the aperture axis; and
`a removable plate selectively fixed to the sidewall of the
`coupler occluding a portion of the aperture correspond-
`ing substantially in size and shape with the element of
`the safety pin to prevent passage of the distal end of the
`safety pin through the aperture, wherein when the
`removable plate is fixed to the sidewall ofthe coupler the
`portion of the aperture not occluded by the removable
`plate is sized to allow passage of the shaft through the
`aperture when the safety pin is moved in a direction
`corresponding to the aperture axis and the longitudinal
`axis, and wherein the shaft, the distal end and the ele-
`ment are removable through the aperture when the plate
`is removed.
`
`7. The system of claim 6, wherein the element is formed by
`stamping the distal end to flatten and widen it.
`8. The system of claim 6, wherein the distal end is integral
`with the shaft.
`
`9. The system of claim 6, wherein the shaft is substantially
`cylindrical.
`
`Page 10 of 11
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`Page 10 of 11
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`10
`9
`a plate removably fixed to the sidewall of the coupler
`10. The system of claim 6, wherein the shaft has one or
`occluding a portion of the aperture, the portion of the
`more flat sides.
`aperture not occluded by the plate corresponding sub-
`11. A system for retaining engagement of first and second
`stantially in size and shape with a cross-section of the
`elements within a coupler, the system comprising:
`shaft of the safety pin, the safety pin being translatable
`a coupler haVing a sidewall and a circular aperture formed 5
`along the longitudinal axis within the aperture with the
`therthrough;
`plate preventing passage of the distal end of the safety
`a safety pin inserted into the circular aperture, the safety
`pin through the aperture.
`pin comprising a head, a shaft depending from the head
`12. The system of claim 11, wherein the shaft is semi-
`al