Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02274236 2003-02-12
ASSEiVIBLY FOR F'AS~i EN t~iCi ..1 'I tOOTH 1'O A?V AD.APTOR
FIELD OF THE IlvIVENTION
The' present invention is related to the field of assemblies for fastening
ground
engaging teeth to adaptors of powered equipment.
BACKGROUND OF THE INVEIW'lON
Many types of excav<xting equipment utilia replaceable ground engaging teeth.
These
teeth erode through use and are r~placc;c.i as needed. Depending on tlne
conditions, a given
adaptor would be re-equipped with from ~ to 3(? teeth to maintain a sharp
penetrating edge
during excszvation. T'he ease of replacement of the. teeth is important
because it minimizes the
amount of wasted throw-away material and also minimizes the downtime of the
tool.
The prior art assemblies used to attach a t~>oth to the aclaptor consist
mainly of two
designs, the wedge design and the pin desi«n. In the wedge design, the tooth
is joined to the
adaptor by wedges whch am hamnuered into corresponding slots in the tooth and
the adaptor.
This design has the disadvantage that the wedges would often become dislodged
during use
of the excavating equipment. To prevent this problem, the wedge was tack-
welded in place.
however, removal of the wedges be°came clifficull and time consuming.
It also required the
drag-line bucket, for example, to be turned on its front end to gain access to
the wedges.
further, during removal, the wedges hacl a tendency to shatter or break
causing pieces to jam
in the slots and posed a serious safety hazard to workers. Wedge designs are
shown, for
example, in U.S. Patent No. 3,256,Ei22.
Pin assemblies with threaded pins and insc,rts for securing a tooth onto the
adaptor are
disclosed in a number of prior art patents. The threaded insert may be placed
into the adaptor
pin opening with the tooth placed o~wrr the adaptor. A lock washer is often
concentrically
placed over the pin opening on the tooth and the pin screwed into the insert.
These types of
assemblies have the disadvantage of being cumbersome and complex in design
making it
difficult to use and increasing the time needed to replace the tooth. As well,
the pin has a
tendency to loosen from the insert while the tooth is in use. Another type; of
pin assembly is
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shown in U.S. Patent No. 3,410,010 which discloses a dipper tooth having a
detent and key
assembly inserted into a passage in the tooth and adaptor. This assembly
suffers from the
drawback that the key would often fall out of the passage during use of the
tooth allowing the
tooth to fall off the adaptor.
There is therefore a need for an assembly to attach a removable excavating
tooth to an
adaptor in such a way that the assembly is easy to use, reliable, and
economical to
manufacture. There is also a need for an assembly for attaching a lip shroud
to a bucket lip to
reduce wear on the bucket lip. With the increase in worker safety awareness,
it is particularly
important that such assemblies be easy to install and do not pose a danger to
workers.
SUMMARY OF THE INVENTION
The present invention provides an assembly for locking an excavating tooth or
lip
shroud to an adaptor or bucket lip wherein the tooth or lip shroud has a slot
in the lower
surface of one end opposite to the point and a first opening in its upper
surface extending into
the slot; the adaptor or bucket lip having a boss on its upper surface
corresponding to the slot
in the tooth or shroud wherein when the tooth or shroud is slid onto the
adaptor or bucket lip,
the slot engages the boss, the assembly comprising pin carrier means slidably
receivable into
the slot in the tooth or shroud; and having a pin receiving opening on its
upper surface
aligning with the first opening in the tooth or shroud when the pin carrier
means is inserted
into the slot; and pin means for insertion into the pin receiving opening of
the tooth or shroud
and receivable in the pin carrier means; the pin engaging the tooth or shroud
and the pin
carrier means for locking the tooth or shroud on to the adaptor or bucket lip.
The assembly
may also include magnetic means for attracting the pin and the pin carrier.
The present invention also provides for a method of retaining a pin in a pin
carrier
comprising the steps of sliding a tooth over the working end of an adaptor,
the adaptor
having a boss on a surface, the tooth having a slot for slidably receiving the
boss and a pin
opening; inserting a pin carrier into the slot until it aligns with the pin
opening in the tooth,
the pin carrier engaging a inner surface of the tooth; and inserting a pin
into the pin opening
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in the tooth and engaging the pin carrier. The method may further include the
step of
magnetically attracting the pin and the pin carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described and may
be
better understood when read in conjunction with the drawings in which:
Figure 1 is a top view of a lip shroud and, in particular, the point of the
lip shroud.
Figure 2 is a view taken through the center line of the shroud and the lip of
the bucket.
Figure 3 is a cross sectional view taken at line A-A shown of Figure 2.
Figure 4 is a top view of the pin hole opening shown in Figure 1.
Figure 5 is a cross sectional view taken at line C of Figure 2.
Figure 6 is a cross sectional view taken at line D of Figure 2.
Figure 7 is a side cross sectional view of the shroud and bucket lip taken at
line B of
Figure 1 but depicting a conventional boss in the pin carrier slot along with
the pin
and pin carrier of the present invention.
Figure 8 is a top view of a pin carrier.
Figure 9 is a side view of the pin carrier.
Figure 10 is a side cross sectional view of the pin carrier taken at line B of
Figure 8.
Figure 11 is an end cross sectional view of the pin carrier taken at line A of
Figure 8.
Figure 12 is a top view of a pin.
Figure 13 is a side cross sectional view of the pin taken at line A of Figure
12.
Figure 14 is an end view of the pin.
Figure 15 is a top view of a pin carrier slot adaptor.
Figure 16 is a side cross sectional view of the pin carrier slot adaptor taken
at line B
of Figure 1 S.
Figure 17 is a side view of the pin carrier slot adaptor taken at line A of
Figure 15.
Figure 18 is a cross sectional view of the pin carrier slot adaptor taken at
line A of
Figure 1 S.
Figure 19 is a side cross sectional view taken at line B of Figure 7.
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Figure 20 is a side cross sectional view taken at line A of Figure 7.
Figure 21 is a side cross sectional view taken at line C of Figure 1.
Figure 22 is a top conceptual view of a pin of the present invention.
Figure 23 is a side cross sectional view of the pin of Figure 22.
Figure 24 is a top conceptual view of a pin carrier of the present invention.
Figure 25 is a side cross section view of the pin carrier of Figure 24.
Figure 26 is a top conceptual view of the pin of a further embodiment of the
present
invention.
Figure 27 is a side cross sectional view of the pin of Figure 26.
Figure 28 is a top conceptual view of a pin carrier of a further embodiment of
the
present invention.
Figure 29 is a side cross sectional view of the pin carrier of Figure 28.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is an assembly and method for locking and unlocking an
excavating tooth or lip shroud to an adaptor or bucket lip. The assembly
allows a person to
easily lock and remove the tooth or shroud with little chance of injury as
compared with prior
art methods and assemblies. The assembly comprises a pin and pin carrier, and
preferably
uses magnets to help hold the pin in the Garner during use.
An excavating tooth or lip shroud generally has a triangular shaped cross-
section and
is formed so as to be received over the working end of an adaptor or bucket
lip as shown in
the side view in Figures 2 and 7. It has a thick section near its tip which
comes to a general
point P for engaging the ground when placed on the working end of the adaptor
or bucket lip
Q. Extending from the point P along the bucket lip are two arms. The first arm
3 extends
along the upper portion of the bucket lip. The second arm 5 extends along the
lower portion
of the bucket lip and is shorter and thinner in diameter than the first arm.
Between these
arms, there is defined an area for receiving the working end of the adaptor or
bucket lip Q.
When the tooth or lip shroud is placed on the adaptor or lip, the inner
surface 21 of the tooth
or shroud engages the outer surface 19 of the adaptor or bucket lip. The point
P of the tooth
CA 02274236 2003-02-12
or shroud has hard facing 9 on its surfai:e. as shown in Figure 1, to e:atend
its life and reduce
its rate of wear. The; working end of tlrc; adaptor or lip has tit pads 1 ~ an
its outer surface 19
(shown in Figures 19 and 20) positioned under the first arm 3 of the tooth for
receiving the
pin carrier which will be described irr ~r~ort: detail beaow. 'I im m pads 17
are raised ridges on
the adaptor or bucket lip. The pin carrier is positioned between the fit pads
when the present
invention is assembled.
The outer surface of the adaptor or bucket lip is fitted with a boss 34 (shown
in
Figures 7 and 20) or may already have a boss extending therefrom. 'The boss 34
is preferably
dovetailed in shape however other i;mbodiments may be used. Particularly where
a dovetail
configuration is not used, a dovetail boss adaptor may be used to ensure a
tight fit with the
tooth or lip shroud.
The; first arm 3 of the tooth or shroud slauw n in Figures 1 and ? has an
outer surface
1 l, inner surface 21 and an end surface ? 3. The tooth or lip shroud has a
standard lifting lug
15 on its outer surface. 1 1. T'he upper surfai:e 1 1 i. f the tootle or lip
shroud 13 has an elongated
opening 37 perpendicular to its longitudinal axis and corrvshoniting to tire
shape of the pin
43. This opening is adapted to receive tlue pin 4:3 when tine ,present
invention is fully
assembled as will be described in more detail below. This pin opening 3 7 is
shown in more
detail in Figures 6 arid 19. It has end walls 39 wh.ch slope inwardly and may
end with a ledge
41 extending inwardly into the pin opening 37 at the lo~.ver end of the
opening.
The end surface 23 of the lip shroud 13 ha~~ an opening extending into a pin
carrier
slot 27. The slot 27 extends through tine lower portion of the lip shroud
along the longitudinal
axis of the adaptor and tooth. The pir~ carrier slot ;'7 is a recess cut into
the lower surface of
the lip shroud 13 and comprises an inner end wall 29. upper wall 31, and side
walls 32, 33.
Thc: side walls 32, 33 of the slot 27 are shown in rnorc detail in Figures S,
6, 19 and
20. They are preferably angled inwardl~~ in a di>vr~tail shape to engat're the
dovetail boss.
Figures 5 auu a show an angle of approximately ~ U° however, any angle
and shape may be
used which allows the slot to engage tlw boss. 'the tooth or shroud is slid
over the adaptor or
lip so that the slot 2~ of the tooth or shroud slidably engages the boss 34.
When the tooth is
slid over the adaptor, the boss engag:;s the inner end wall 29 of the lip
shroud 13. While the
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boss 34 is ;preferably a dovetail shaped boss, other configurations may used.
Dovetail
adaptors n,uly be fitted around the boas in order to achieve a dovetail
c;onllguration or other
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t17~.' lll) ShCOtld 177 ay f,'ngilg~'. the bOSS.
One example is show. in Figures 1 5-18. These Fib ures depict a dovetail
adaptor 45 which
has an inner ridge 4 7 for engaging a rlora-dovetail boss. The, outer walls 49
c>f the dovetail
;adaptor 45 are shaped so as to correspond to the inner side walls 32. 33 of
the pin carrier slot
27 for engagement and retention with the slot.
The assembly c>fthe present invention inch-Ides a pin carrier 35 shown in more
detail
.n Figures 8-1 l, 24, 25, 28 and 29. The pin carrier- 35 is elongated having
an end wall 51
extending upwardly and a generally flat elongated lower section 53 extending
from the lower
end of the end wall 51. The outer portion of the lower section 53 may extend
at a downward
angle providing a tapered end 59 to the pin carrier .35. The upper surface of
the lower section
53 contains receptacles 5.5 for magnets 57. 'these rec~ptacies are sho~~,~n as
three round areas
in Figures 8 and 10, however, other arrangements of magnets may be used. An
example is
shown in Figures 28 and 29.
The pin carrier 35 may be slidahly il7serte~ into the pin carrier slot 27
through the
opening in the end surface 23 of the lip shroud 13. It is fully inserted when
the pin carrier is
in alignment with the pin opening 37 ill the lip shroud. The boss 34 extends
from the rear
wall of the lip shroud to the pill opening. The rear surface of the boss is
positioned forward of
the pin opening towards the point of the tooth so that the pin carrier n7 ay
be inserted into the
slot and positioned under the pin opening and against the boss. Tl7e pin
receiving opening 37
in the upper surface of the lip shroud 13 and the il~serted pin carrier define
a pin receiving
chamber.
The pin 43 is shown in Figures 1'2-14, 22, '?3, 26 and 27. It is an elongated
piece
having one end with a lip portion 61 <lnd the opposin~T end with openings 63,
65 therein. The
pin 43 n7ay be inserted through the pin opening 3 ; in ul~ 1111 shroud 1 s
into the pin receiving
chamber. A, portion of the pin 43 ten 7ains i n the pin opening 37 in the lip
shroud 13 and may
extend therefrom. The lip 61 at one end of the pin =13 engages tile lower
surface of the; lip
shroud 13 as shown in Figure 19. The lip 61 helps to maintain the pin 43 in
the pin receiving
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opening 37. The pin 43 is made of a material which will be drawn to the
magnets and
preferably is steel. The magnets 57 are arranged and aligned so as to attract
the pin 43 to the
pin carrier 35 retaining it in the pin receiving slot 27. The magnetic
attraction of the pin 43 to
the pin carrier 35 is sufficient to maintain the pin 43 in the pin receiving
opening 37 in the lip
shroud 13 and thereby maintain the lip shroud on the working end of the bucket
lip during
use.
To remove the pin 43 from the pin carrier 3 S, a pry bar or other similar tool
may be
used. One end of the pry bar is inserted into the upper opening 63 in the end
of the pin 43 by
insertion down the angled wall of the pin opening 37 in the lip shroud as is
shown in Figure
19. The protrusion at the lower end of the opening and the angled wall provide
leverage and
support for the pry bar. The pry bar is forced into the opening 63 and is used
to leverage the
pin 43 out of the pin carrier 35. If necessary, the pin may be partially
removed and the pry
bar inserted into the second lower opening 65 in the pin to further leverage
it out of the pin
opening in the lip shroud. As the pin is lifted and moved away from the pin
carrier and the
magnets, the magnetic force on the pin will decrease thereby releasing the
pin. Once the pin
is removed, the pin carrier and the lip shroud may be removed from the end of
the adaptor
and the tooth replaced.
An alternative embodiment of the pin is shown in Figures 26 and 27. These
Figures
shown a pin cylinder 67 near one end of the pin. It may be manually rotated 90
° about its
center axis. It contains a plurality of magnets 69 on its lower surface. The
pin carrier contains
a matching plurality of magnets on its upper surface. The poles of these
magnets are arranged
so that with the cylinder 67 rotated to the lock position, the pole alignments
for the pin and
carrier magnets are such that the pin and retainer are strongly attracted
together thereby
holding the pin firmly in place. When the cylinder is rotated 90° to
the unlocked position, the
alignment of poles between the pin and carrier magnets reverses and the
magnetic forces
become repulsive. The pin is thus easily removed from the opening by hand.
Since the pin may be easily removed by a worker with a pry bar, it poses
little danger
to workers. There is less chance of injury to workers in removing and
replacing teeth. As
well, standard assemblies to attach teeth to adaptors often fail during use.
With the present
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g
invention, the magnetic attraction of the pin to the pin carrier is unlikely
to fail causing
injury to nearby workers.
The above-described embodiments of the present invention are meant to be
illustrative of preferred embodiments and are not intended to limit the scope
of the present
invention. Variations of the invention will be readily apparent to persons
skilled in the art
and may be made without departing from the spirit or scope of the invention.
These
variations are intended to be within the scope of the present invention. The
only limitations
to the scope of the present invention are set out in the following appended
claims.
