Note: Descriptions are shown in the official language in which they were submitted.
LOCKING PIN APPARATUS
TFC)F)~CA>L, FIELD OF T~iE ~ENNTION
The present invention relates generally to earth excavating equipment, and
more
particularly provides an improved locking pin apparatus that is used to
captively retain a
replaceable excavating tooth point on the nose portion of an adapter which, in
tum, is
secured to the forward lip of an excavating bucket or the like.
EACKGROUI~lI3 ~F T)<IE IN~F~TTIO1~1
Excavating tooth assemblies provided on digging equipment such as excavating
buckets or the like typically comprise a relatively massive adapter portion
which is suitably
ancl~oxed to the forward bucket lip and has a reduced cross-section, forwardly
projecting nose
1~0 portion, and a replacec~blo tooth point having formed through a rear end
thereof a pocket
opening that releasably receives the adapter nose. To captively retain the
paint on the
adapter nose, aligned transverse openings are formed through these
interengageable elements
adjacent the rear end of the point, and a device commonly referred to as a
flex pin or locking
pin is driven into these openings.
While locking pins have a variety of configurations, a widely used version, as
representatively illustrated in U.S. Pat. No. 3,526,049 to Nichols and U.S.
Pat. No.
3,685,175 to Ratkowski, typically comprises elongated, straight metal locking
and wedge
members which are laterally spaced apart and intersecured by an elongated
central
ela~stomeric element. As the locking pin is being driven into the aligned
point and adapter
nose openings, the elastomeric element is compressed and, when the pin is
driven to its
installed position, laterally urges a detent portion formed on one of the two
metal portions
of the point into engagement with a suitably configured portion of the adapter
nose to
captively retain the flex pin within the point and adapter openings. With the
flex pin in its
operative position within such openings, the elastorneric element is in a
state of partial
compression, rear surfaces of the tooth point openings bear against opposite
end portions of
the locking member, and a forward surface of the adapter nose opening bears
against a
longitudinally central portion of the wedge member. Forwardly directed tooth
point removal
2128~~~
-2-
forces encountered during the excavating process cause the tooth point to be
driven forwardly
relative to the adapter to thereby move the locking member closer to the
elastomeric element,
the opposite ends of the Locking member preventing farwaxd removal of the
tooth point.
Two primary problems and disadvantages are present in this type of
conventional flex
pin construction -- each of which is related to failure of the central
elastomeric element.
First, as the flex pin is being driven into the aligned tooth paint and
adapter nose openings
the locking and wedge members tend to be moved longitudinally relative to one
another.
Thus, if the driving-in gxocess is not carefully performed, this relative
longitudinal movement
can easily shear the elastomeric element, thereby ruining the flex pin.
Secondly, excessive
IO forwardly directed tooth point removal loads can laterally move the locking
member close
enough to the wedge member to ovexcompxess and thereby split the elastomeric
element.
Various attempts have previously been made to bettex protect the critical
central
elastomeric portion of the flex pin by altering the essentially straight
configuration of the
locking and wedge member portions utilized in flex pin structures such as
those depicted in
IS the Nichols and Ratkowski patents. One such proposed solution, as
exemplified in U.S. Pat.
No. 4,192,089 to Schwappach and U.S. Pat. No. 4,446,538 to Novotny et al., is
to form a
central lateral recess in a front side portion of the locking member and to
shorten the wedge
member so that it is laterally movable into such recess against the resilient
force of the
central elastomeric element. With the elastomeric element in an uncompressed
condition the
20 opposite ends of the wedge member underlie the opposite end surfaces of the
recess so that
as the flex pin is being driven into the point and adapter openings one of the
wedge member
ends is driven into engagement with its adjacent recess end surface. This
limits the relative
longitudinal travel between the locking and wedge members to thereby limit the
shear stress
imposed upan the elastomeric element.
25 In an attempt to similarly limit the lateral compressive stress imposed on
the
elastomeric element, the maximum distance which the wedge member may be
laterally
moved into the locking member recess is limited to a distance less than the
front-to-rear
thickness of the elastorneric element by causing opposite end portions of the
wedge member
to rigidly engage portions of the lacking member during travel of the wedge
member into the
30 locking member recess. In the Schwappach patent this inward travel
limitation is achieved
by foaming on the opposite wedge member ends rearwardly directed projections
which are
engageable with the rear side surface of the lacking recess. In the Novotny et
al patent a
2.~286~2
-3-
similar result is achieved by forming forwardly facing shoulders posited
adjacent opposite
ends of the recess which are adapted to rigidly engage opposite end portions
of the wedge
member during its lateral travel into the recess. Somewhat similar schemes for
protecting
elastomeric flex pin portions are evidenced in U.S. Pat. No. :2,927,387 to
Drover and U.S.
Pat. No. 3,126,654 to Eyolfson et al.
While this conventional method of limiting lateral compression of the
elastomeric
element represents an improvement over somewhat simpler flex pin structures
such as those
depicted in the Nichols and Ratkowski patents, it creates significant
structural problems in
the wedge member. Specifically, when the wedge member is moved to its
°°stopped" position
within the locking member recess a large rigid bending load is imposed thereon
by the
forward surface of the adapter nose opening which bears against a central rear
side portion
of the wedge member. To adequately strengthen the wedge member against such
bending
load it is necessary to appropriately increase its front-to-rear thickness.
This thickening, in
tum, typically requires that undesirable design modifications be made to one
or all of the
elastomeric elements, the locking member and the adapter nose opening.
Specifically, it is well known that the overall strength of an adapter nose
is, generally
speaking, inversely proportional to the size of the flex pin opening formed
therethzough.
Thus, if it is desired to maintain a given front-to-rear length of the adapter
nose opening, the
necessary thickening of the wedge member requires that the front-to-rear
thickness of one or
both of the elastorneric element and the locking member be coraespondingly
reduced.
Reducing the thickness of the locking member, of course, structurally weakens
the flex pin,
while reducing the thickness of the elastomeric element reduces the resiliency
of the flex pin
and the potential lateral travel between its rigid elements. Of course,
neither of these results
is desirable.
If, on the other hand, the front-to-rear thickness of the elastomeric element
and the
locking member are maintained, the thickening of the wedge member requires
that the
front-to-rear length of the adapter nose opening be correspondingly increased.
This, of
course, undesirably weakens the adapter nose.
Therefore, a need exists for a locking pin which eliminates the use of an
elastomeric
element altogether. Such a locking pin would not experience the problems o:~
dimensional
limitations due to the thickness of the elastomeric element. Nor would it be
limited to
environments safe for elastomeric materials. A need exists for a one-piece
locking pin,
CA 02128642 1999-08-23
thereby eliminating the need to store various elements at the job site. A one-
piece design
would also limit the risk of error in installing the locking pin.
SZIrvIMARY OF T'~ T~IVVENTION
A locking pin assembly is provided which overcomes many of the disadvantages
found in the prior art. Namely, the preferred embodiment of the present
locking pin does
not invokve multiple elements, instead its one-piece design allows for easier
storage at the job
site and easier installation and removal. The preferred embodiment can be
formed by metal
casting thereby eliminating the use of any ekastomeric material. This allows
the locking pin
to be used around caustic or hot environments where prior art locking pins can
fail.
The locking pin of the present invention has ~ a generally elongated shape
with a
proximal end and a distal end. The proximal end serves as an impact surface
while the distal
end is dimensioned to guide the locking pin during insertion. A first positive
stop means can
extend outward from the proximal end of the pin. This first positive stop
means limits the
travel of the pin during insertion. An integral spring is formed by a pkanar
extension angled
from the pin and extending upward from the distal end. The integral spring
allows for
compression during insertion, but resumes. its normal position after
insertion. A second
positive stop means extends from the integral spring. This second stop means
prevents
removal of the pin from a direction opposite to the direction of insertion.
Therefore, to
remove the locking pin after its insertion, a sufficient force must be applied
to the pin's
proximal end to break off the first stop means. This allows the pin to then be
driven through
the interengaged tooth and adapter.
In an alternative embodiment, the locking pin also incorporates vibration
dampening
means. This dampening means may be either an elastomeric element or a second
integral
spz~ng. In another embodiment, the pin is provided with a circular cross-
section.
In another embodiment, the locking pin is provided with an integral spring on
one
side and a guide means. The integral spring extends from the distal end of the
wedge
member on a lateral side of the locking pin. A guide means also extends from
the wedge
member near its distal end. The guide means helps turn the pin into a vertical
position while
the pin is driven into the tooth and adapter assembly. In another embodiment,
the locking
pin comprises stop means which are radially extendable by spring means.
CA 02128642 1999-08-23
>-
-5-
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and for further
details
and advantages thereof, reference is now made to the following Detailed
Description taken
in conjunction with the accompanying drawings, in which:
FIGURE 1 is a perspective of the one-piece locking pin;
FIGURE 2 is a side view of the one-piece locking pin;
FIGURE 3 is a top view of. the proximal end of the one-piece locking pin;
FIGURE 4 is a sectional view across section line 4-4 in FIGURE 2;
FIGURES 5-8 illustrate the steps of inserting the one-piece locking pin
between the
adapter portion and the replaceable tooth;
FIGURES 9A and 9B disclose an alternate locking pin embodiment with vibration
dampening elements;
FIGURES 10A and lOB disclose an akternate one-piece locking pin embodiment
with
vibration dampening elements;
FIGURES l IA and 11B disclose an alternate one-piece locking pin embodiment
with
vibration dampening elements and perpendicularly disposed first and second
stop means;
FIGURES 12A and 12B illustrate a one-piece locking pin with circular cross-
section
and a secant integral spring groove;
FIGURES 13A and 13B illustrate a one-piece locking pin with a circukar cross-
section
and a U-shaped integral spring' groove; and
FIGURE 14 is a perspective view of a first embodiment of a side spring locking
pin
having a distal guide means;
FIGURE 15 is a side view of the first embodiment of the side spring locling
pin
having a distal guide means;
FIGURES 16, 17, and 18 illustrate a method of inserting a side spring locking
pin;
FIGURE 19 is a side view of a second embodiment of the side spring locking pin
having a rigid plate and elastomer compression element;
FIGURE 20 is a side view of a third embodiment of the side spring locking pin
having flexible curved compression element;
FIGURE 21 is a sectional view across line 21-2k in Figure 20, showing the
third
embodiment of the side spring locking pin having tapered grooves in a
compression element slot
which engage the flexible curved compression element;
CA 02128642 1999-08-23
r
FIGURE 22 is a sectional view, illustrating the flexible compression element
in a
compressed and deformed state;
FIGURE 23 is a sectional view across the adapter and tooth assembly showing
the
side spring extending under the tooth to prevent withdrawal of the locking
pin;
FIGURE 24 is a sectional view of a locking pin having radially retractable
stop
means; and
FIGURES 25 and 26 are sectional views of the locking pin shown in FIGURE 24
being inserted into the interengaged tooth and adapter assembly.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an improved one-piece locking pin apparatus
that is
used to captively retain a replaceable excavating tooth point on the nose
portion of an adapter
which, in turn, is secured to the forward lip of an excavating bucket or the
like. Referring
to FIGURE 1, a locking pin 100 embodying the present invention is shown in
perspective.
Pin 100 is comprised of a wedge member 110 with a proximal end 114 and a
distal end 116.
An integral spring 120 is formed on a first side 102 of wedge member 110 while
a first
positive stop means 130 extends from an opposite side 104 of wedge member 110.
Pin 100
can be made of 4140 steel or similar metal such that integral spring 120
cannot be over
stressed past its yield point.
Refernng to FIGURES 1 and 2 simultaneously, locking pin 100 has a generally
rectangular shape. Proximal end 114 is typically flat while distal end 116
comprises several
angled surfaces 116a, 116b, and 116c. As will be discussed in greater detail,
proximal end 114
acts as an impact surface while distal end surfaces 116a, 116b, and 116c act
to guide locking pin
100 into position between an adapter and a replaceable tooth. A first distal
angle exists at point
116d between the first surface 102 and the first distal surface 116c, a second
distal angle exists at
point 116e between the first and second distal surfaces 116c, 116b, a third
distal angle exists at
point 116f between the second and third distal surfaces 116b, 116a, and a
fourth distal angle
exists at point 116g between the second surface 104 and the third distal
surface 116a. Each of
said first, second, third, and fourth distal angles are being greater than or
equal to 90 degrees.
The first positive stop means 130 may have a stop surface 132 and a slide
surface 138. The
distance between connection points 134 and 136 is small, thereby making the
first positive stop
means 130 frangible.
Integral spring 120 extends outward from side 102 of wedge member 1I0. The
integral spring 120 can be connected to the wedge member 110 generally near
its distal end
CA 02128642 1999-08-23
_7_
116. The integral spring 120 is typically a resilient, planar member with a
second positive
stop means 122 at its remote end. Integral spring 120 may flex inward toward
wedge
member 110 during its insertion. Due to its resilient nature, the integral
spring 120 will
resume its normal position upon reaching a locking position. Stress relief
surface 124 deters
crack formation and propagation between the spring 120 and the wedge member
110. A
support 128 formed on spring 120 deters the deformation of second positive
stop means 122.
FIGURES 3 and 4 illustrate the trapezoidal cross-section of this embodiment of
the
locking pin 100. Proximal end 114 is best shown in FIGURE 3. Side 114a of
proximal end
114 is narrower than side 114b. This "key" effect prevents the improper
insertion of the
locking pin 100. FIGURE 4 illustrates a sectional view across section line 4-
4. in FIGURE
2. The spacing between integral spring 120, wedge member 1I0 and first
positive stop
means 130 is clearly shown.
FIGURES 5 through 8 illustrate a method of inserting the locking pin 100 into
a
forward end portion of an excavating tooth and adapter assembly 10 which
includes an
adapter portion 12, and a replaceable tooth point 14 which is removably
secured to the
adapter. The adapter has a rearwardly disposed base portion 18 which may be
suitably
secured to the lower forward lip of an excavating bucket or the like (not
illustrated) to
support the point of tooth 14 in a forwardly projecting orientation relative
to the bucket lip.
Together with other similar tooth and adapter assemblies, the assembly 10
defines the digging
2p tooth portion of the overall excavating apparatus.
The tooth 14 is provided with vertically tapered upper and lower side wall
portions
and 22 which converge at the forward end to a point (not shown) to define a
cutting edge.
Extending forwardly through the rear end 26 of tooth I4 is a vertically
tapered pocket
opening 28 that receives a complementarily tapered nose portion. 30 which
projects forwardly
from the adapter base 18 and defines therewith a forwardly facing peripheral
shoulder portion
32 that faces and is spaced slightly rearwardly from the rear end 26 of the
tooth 14.
The tooth 14 is respectively provided along its upper and lower side walls 20
and 22
with raised reinforcing portions 34 and 36 through which aligned, generally
rectangular
cross-sectioned openings 38 and 40 are respectively formed. Openings 38 and 40
are
elongated in a direction parallel to the longitudinal axis 42 of the assembly
10 and have
forward end surfaces 44 and 46 which are generally perpendicular to axis 42,
and forwardly
and outwardly sloped rear surfaces 48 and 50. Aligned with the tooth point
openings is a
CA 02128642 1999-08-23
_8_
generally rectangulariy cross-sectioned opening 52 extending vertically
through the adapter
nose 30. Opening 52 has an essentially flat rear end wall 54, and a forward
end wall 56.
The present locking pin 100 is received in the aligned tooth and adapter nose
openings 38,
40 and 52 and functions in a manner subsequently described to captively retain
the tooth 14
on the adapter nose 30 and prevent its separation therefrom. FIGURE 5 shows
the initial
insertion of distal end 116 of locking pin 100 through tooth opening 38 and
into adapter
opening 52. Integral spring 120 contacts outwardly sloped rear surface 48 of
tooth 14. Point
116g of the distal end of locking pin 100 contacts surface 54 of tapered nose
portion 30.
Upon further insertion into adapter opening 52, the locking pin 100 tilts,
thereby producing
contact between distal point 116d to forward wall 56; as shown in Fig. 6.
Wedge member
side 104 contacts surface 54 of tapered nose portion 30. Outwardly sloped rear
surface 48
moves upward along integral spring 120.
FIGURE 7 shows the locking pin 100 in almost a completely inserted position.
Outwardly sloped rear surface 48 contacts second positive stop means 122 as
integral spring
120 is forced to a compressed position. First positive stop means 130 enters
opening 38 in
tooth 14. Also, distal point 116d moves lower on rearward wall 56 while distal
surface 116c
contacts sloped rear surface 50. Further downward force exerted on locking pin
100 causes
the pin to straighten due to the taper of distal surface 116c. This
straightening causes second
positive stop means 122 to further slide downward on rear surface 48.
After a predetermined distance of slide the second positive stop means 122
disengages
rear surface 48 and integral spring 120 returns to its non-compressed position
as shown in
FIGURE 8. Simultaneously, first positive stop means 130 contacts nose portion
30.
Furthermore, the distal portion of surface 102 engages rearward surface 50. In
its final
insertion position, locking pin 100 is incapable of being forced further into
openings 38, 40
or 52 without extreme deformation of either first positive stop means 130 or
adapter nose 30.
Nor can the locking pin 100 be withdrawn from openings 38, 40 or 52 without
extreme
deformation of integral spring 120 or second positive stop means 122.
Therefore, the pin
100 is locked into position and prevents the separation of adapter 12 from
tooth 14. To
remove locking pin 100 from this position, a predetermined force must be
applied to surface
114 to break first positive stop means 130 from the wedge member 110, thereby
allowing
the pin 100 to be completely driven through opening 40. Note that proximal
surface 114 is
positioned below the height of either upper side wall portion 20 or raised
reinforcing portion
CA 02128642 1999-08-23
_g_
34. Thus, the proximal surface 114 is protected from unwanted impact which
could
accidently break off first positive stop means 130. Also, during insertion,
the inserter can
easily determine when to stop applying force to the proximal surface 114 based
upon a visual
inspection of its position.
FIGITRES gA and 9B illustrate locking pin 200, an alternative embodiment of
the
invention. While this pin 200 is not a single-piece unit, it shares many of
the same features
of pin 100. For example, pin 200 has a proximal end 214 and a distal end 2I6
dimensioned
to aid in the insertion of the pin between adapter 12 and tooth 14. Locking
pin 200 further
has a first and second positive stop means 230, 222 similar in shape and
function to those
described for loclang pin 100. However, pin 200 has additional vibration
dampening features
including bearing element 240. Bearing element 240 can be attached to wedge
member 210
by at least one resilient member 242. These resilient members 242 can be made
of materials
including neoprene or other vibration dampening materials. Bearing element
240, upon
insertion, firmly contacts rear end wall 54. Thus, vibration from the normal
use of the
excavating equipment may be transmitted from the tooth to the locking pin 200,
whereupon
it is largely diminished prior to its transmission to adapter 12.
FIGURES 10A and lOB illustrate yet another alternate embodiment. Locking pin
300,
again has similar features to pin 100, including a proximal end 314 and distal
end 316
dimensioned to aid in the insertion of the pin between adapter 12 and tooth
14, as well as a first
and second positive stop means 330, 322 similar in shape and function to those
described for
locking pin 100. Locking pin 300 controls vibration with a second integral
spring 340 which
firmly contacts rear end wall 54 after insertion. Second integral spring 340
extends upward from
distal end 316 in a generally curved fashion. Stress relief surface 342 is
provided to deter crack
formation and propagation. Again, as vibration is transmitted from tooth 14 to
pin 300, second
integral spring 340 minimizes transmission of said vibration from pin 300 to
adapter 12.
Locking pin 300 is removed in similar fashion to each locking pin described.
Excess force is
applied to proximal end 314, breaking first positive stop means 330 from the
pin. The pin 300
may then be driven through the assembly, thereby allowing removal and
replacement of tooth 14.
FIGURES 11 A and 11 B disclose yet another variation of the present invention
with
locking pin 400. Locking pin 400 also has a second integral spring means 440
extending from
the distal end 416. However, a second positive stop means 422 extends
perpendicularly from
wedge member 410. This relationship is better shown in FIGURE 11 B. This
configuration
allows for a slightly wider locking pin. First positive stop means 430 is
similar in shape and
function as described for locking pin 100.
CA 02128642 1999-08-23
-10-
FIGURES 12A and 12B and FIGURES 13A and 13B disclose horizontal locking pin
embodiments 500 and 600. Both embodiments feature a generally circular cross-
section with
an integral spring 520, 620 extending upward from a midsection of wedge
members 510,
610. Integral spring 520, shown in FIGURES 12A and 12B, comprises the entire
arc formed
by secant groove 524 which divides the integral spring 520 from the wedge
member 510.
FIGURES 13A and 13B illustrate an integral spring 620 separated from the wedge
member
610 by a U-shaped groove 624. Both embodiments utilize a first positive stop
means 530,
630 and a second positive stop means 522, 622 as in previously described
embodiments.
Both first positive stop means are located in opening 38. Thus, circular
locking pins 500,
600 cannot rotate sufficiently to allow integral spring means 520, 620 to
escape through
opening 38. Note also that first stop means 530, 630 do not contact adapter 12
when
inserted. Instead, contact occurs only when the locking pins 500, 600 are
forced further into
the assembly than normal. In order to drive locking pins 500, 600 out of
position, a tool
adapted to insert into opening 38 must contact the pins. Force is then applied
to cause first
stop means 530, 630 to contact adapter 12 and break off. The pin may then be
driven out
of the assembly.
Referring to FIGURFS 14 and 15 simultaneously, locking pin 700 has a generally
rectangular shape. Proximal end 714 is typically flat while distal end 716
comprises several
angled surfaces 716a, 716b, 716c. As with earlier described embodiments,
proximal end 714
2~ acts as an impact surface, while distal end surfaces 716a, 716b, and 716c
act to guide locking pin
700 into position between an adapter and a replaceable tooth. A first distal
angle exists between
the first surface 702 and the first distal surface 716c, a second distal angle
exists between the first
and second distal surfaces 716c, 716b, a third distal angle exists between the
second and third
distal surfaces 716b, 716a, and a fourth distal angle exists between the
second surface 704 and
the third distal surface 716a. Each of said first, second, third, and fourth
distal angles are greater
than or equal to 90 degrees. First and second surfaces 702, 704 are generally
parallel while the
third and fourth surfaces 706, 708 are tapered toward each other to producer a
trapezoidal cross-
section. This "key" effect prevents the improper insertion of the locking pin
700.
A first stop means 730 extends from the second surface 704 near the proximal
end
714. The first stop means 730 can have a stop surface 732 and a slide surface
738. The
first stop means prevents unwanted downward motion of the locking pin after
its insertion.
2~.286~2
-11-
The distance between connection points 734 and 736 is small, thereby making
the first stop
means 730 frangible. Integral spring 720 extends outward :from third side 706
of wedge
member 710. The integral spring 720 can be connected to the wedge member 710
generally
near its distal end 716. The integral spring 720 is typically a resilient,
planar member with
an unconnected proximal end which acts as a second stop am°ans 722.
Integral spring 720
may flex inward toward wedge member 710 during its insertion. Due to its
resilient nature,
the integral spring 720 will resume its normal position upon reaching a
locking position.
Stress relief surface 724 deters crack formation and propagation between the
spring 720 and
the wedge member 710. A guide means 750 extends from the first surface 702
near the
distal end 716. As wilt be discussed later, the guide means 750 helps to guide
the locking
pin 700 into position during insertion. Additionally, the guide means 750 acts
as a third stop
means to prevent downward motion of the locking pin. Both the first stop means
730 and
the guide means 750 can be broken from the wedge member 710 by a powerful plow
to the
proximal surface 714. Once these members are broken away, the locking pin 700
can be
driven through the interengaged tooth and adapter assembly. A deformable ridge
752 extends
from second surface 704.
FIGURES 16, 17, 18, and 23 illustrate a method of inserting the locking pin
700 into
a forward end portion of an excavating tooth and adapter assembly 10 wrich
includes an
adapter portion 12, and a replaceable tooth point 14 which is removably
secured to the
adapter. Refer to the discussion of FIGURES 5, 6, 7, and 8 for a more detailed
discussion
of the adapter and tooth point. The present locking pin 700 is received in the
aligned tooth
and adapter nose openings 38, 4U and 52 and functions in a manner subsequently
described
to captively retain the tooth 14 on the adapter nose 30 and prevent its
separation therefrom.
The width of tooth 700 should precisely match the size of the aligned tooth
and adapter
openings. However, if the tooth is slightly smaller than the aligned openings,
a tolerance can
exist between the adapter nose and the tooth after the locking pin is
inserted. This tolerance
leads to an unwanted looseness or "jiggle°' to the tooth. The
deformable ridge 752
compensates for any tolerance. In other words, the ridge 752 extends the width
greater than
the opening in the aligned tooth and adapter. When the locking pin is driven
into the aligned
openings, the ridge 752 can deform, thereby eliminating any tolerance.
FIGURE 16 shows the initial insertion of distal end 716 of locking pin 700
through
tooth opening 38 and into adapter opening 52. Integral spring 720 contacts
lateral wall 45
CA 02128642 1999-08-23
-12-
(shown in FIGURE 23) and compresses toward the wedge member 710. Guide means
750
contacts surface 56 while the deformable ridge 752 contacts surface 54 of
tapered nose
portion 30. Upon further insertion into adapter opening 52, the locking pin
700 tilts back
toward a vertical position. FIGURE 17 shows the locking pin 700 in almost a
completely
inserted position. The guide means 750 forces the pin 700 to a vertical
position. The guide
means 750 allows for the use of a shorter locking pin by diminishing the
importance of a
long distal surface 116c as discussed in FIGURE 7. The integral spring 720 is
forced to a
compressed position. First stop means 730 enters opening 38 in tooth 14. In
FIGURE 18
the locking pin 700 is shown fully engaged between the tooth and adapter
assembly. After
a predetermined distance of slide the guide means 750 contacts the rear
surface 50 of the
tooth. Simultaneously, first stop means 730 contacts nose portion 30. As shown
in FIGURE
23, the adapter is configured with two indentations 60. Either indentation 60
can receive the
integral spring 720 when it disengages lateral surface 45 and returns to its
non-compressed
position. Due to the configuration of the adapter, the locking pin can be
driven into the
interengaged tooth and adapter from either direction.
In its final insertion position, locking pin 700 is incapable of being forced
further into
openings 38, 40 or 52 without extreme deformation of either first stop means
730, guide
means 750 or adapter nose 30. Nor can the locking pin 700 be withdrawn from
openings
38, 40 or 52 without extreme deformation of integral spring 720. Therefore,
the pin 700 is
locked into position and prevents the separation of adapter 12 from tooth 14.
To remove
locking pin 700 from this position, a predetermined force must be applied to
surface 714 to
break first stop means 730 and guide means 750 from the wedge member 710,
thereby
allowing the pin 700 to be completely driven through opening 40. Note that
distal surface
716 is positioned flush with the outer surface of the tooth 20 to protect it
from any impact.
FIGURE 19 illustrates a side spring locking pin 800. Locking pin 800 is
identical to
locking pin 700 except for compression element 860. The compression element
860 absorbs any
tolerance between the tooth, adapter, and locking pin. The compression element
860 fits within a
compression element slot 854 in the second surface 704. The slot 854 has a
rear surface. The
compression element 860 comprises a rigid plate 862 attached to an elastomer
element 864. The
elastomer element 864 can be any suitable material, such as neoprene, which is
elastically
compressible. The rigid plate 862 can be made of the same material s the
locking pin.
CA 02128642 1999-08-23
-13-
When inserted, the rigid plate 862 is forced into the compression element slot
854, thus
compressing the elastomeric element 864 against the rear surface of the slot.
Referring to FIGURES 20, 21, and 22 simultaneously, another version of locking
pin
800 incorporates a semi-rigid compression element 870 in compression element
slot 854.
The semi-rigid compression element 870 is curved and made of a stiff material
such as glass
reinforced nylon. The compression element 870 fits snugly within the slot 854
to prevent
its loss prior to insertion. To help hold the element 870 in place, a pair of
opposed ridge
sets 856 extend into slot 854. In preferred embodiment, two pair of opposed
ridges extend
into the slot 854. Each ridge tapers down from the base of the slot. In a
preferred
embodiment the curved portion of the compression element 870 extends out from
the slot
854. When the compression element 870 is inserted into the slot 854, the
compression
element is slightly wedged by the ridges 856. The compression element 870 will
Oaten once
inserted. Furthermore, a portion of the flattened compression element still
extends beyond
slot 854 and can deform, as shown in FIGURE 22, due to the forces encountered
during
insertion or use. The deformed portion 870a absorbs any tolerance between the
tooth,
adapter, and locking pin.
FIGURE 24 provides a sectional view of another kocking pin embodiment having
radially retractable stop means. Locking pin 900 does not utilize an integral
spring, but
instead has a first and second stop means 910, 912. Both stop means are
received within
radial holes 906. A spring means 908 is located within each radial hole. Both
stop means
have either a retracted or extended position. A sleeve 904 surrounds the
locking pin body,
keeping the stop means in a retracted position. The pin and sleeve are
inserted into the
transversely aligned holes in the interengaged tooth and adapter. The sleeve
904 is then
removed by pulling it axially away from the pin 900. As the sleeve 904 is
removed, first
stop means extends radially into indentation 60. Likewise, when the sleeve 904
is completely
removed, the second stop means 912 will also extend radially. The first and
second stop
means 910, 912 will prevent the upward or downward egress of the locking pin
900. When
the tooth 20 is to be removed from the adapter 30, a force is applied to pin
surface 902 to
break the stop means, thereby allowing the pin to pass through the aligned
openings.
FIGITRFS 25 and 26 illustrate the locking pin 900 being inserted into the
interengaged
tooth and adapter assembly with insertion tool 920. The tool 920 comprises a
handle 922
with a grip 924 and a head 926. The head 926 provides a cam surface 928. The
pin 900
2~~8642
-14-
is driven through the cam surface 928. The stop means 910 is compressed
against the cam
surface, allowing the wedge member to enter the interengaged tooth and adapter
assembly.
Likewise, the stop means 912 is also compressed against cornpression means 908
when it
engages the cam surface. Once inserted, the stop means 910, 912 extend into
indentations
60.
Although preferred embodiments of the invention have been described in the
foregoing Detailed Description and illustrated in the accompanying drawings,
it will be
understood that the invention is not limited to the embodiments disclosed, but
is capable of
numerous rearrangements, modifications and substitutions of parts and elements
without
departing from the spirit of the invention. Accordingly, the present invention
is intended to
encompass such rearrangements, modifications and substitutions of parts and
elements as fall
within the spirit of the scope of the .invention.
