U.S. patent number 3,650,053 [Application Number 04/133,326] was granted by the patent office on 1972-03-21 for roller lock for digging tooth assembly.
This patent grant is currently assigned to Bucyrus-Erie Company. Invention is credited to Josef Baer.
United States Patent |
3,650,053 |
Baer |
March 21, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ROLLER LOCK FOR DIGGING TOOTH ASSEMBLY
Abstract
This invention relates to a lock for the key which holds a
digging tooth point on an adapter. The lock comprises a roller that
is engageable with a recess in the key and is mounted in an
open-ended cage so that it cannot move laterally or longitudinally
with respect to the key but is free to rotate on a transverse axis
and to move toward and away from the key. A rubber backup plug
biases the roller toward the key, but does not prevent its
rotation.
Inventors: |
Baer; Josef (South Milwaukee,
WI) |
Assignee: |
Bucyrus-Erie Company (South
Milwaukee, WI)
|
Family
ID: |
26831267 |
Appl.
No.: |
04/133,326 |
Filed: |
April 12, 1971 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
825124 |
May 7, 1969 |
|
|
|
|
Current U.S.
Class: |
37/457; 175/412;
403/316 |
Current CPC
Class: |
F16B
21/16 (20130101); E02F 9/2841 (20130101); F16B
2/16 (20130101); F16B 21/125 (20130101); Y10T
403/581 (20150115) |
Current International
Class: |
E02F
9/28 (20060101); F16B 21/16 (20060101); F16B
2/02 (20060101); F16B 2/16 (20060101); F16B
21/00 (20060101); F16B 21/12 (20060101); E02f
009/28 (); E21c 013/00 () |
Field of
Search: |
;37/142 ;285/305,403
;287/119 ;175/412,413 ;292/23,75,77,79,73 ;299/91,92,88 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pulfrey; Robert E.
Assistant Examiner: Hanor; C. W.
Parent Case Text
BACKGROUND OF THE INVENTION
This is a continuation of U.S. Pat. application Ser. No. 825,124,
filed May 7, 1969 now abandoned.
Claims
I claim:
1. In a digging tooth assembly of the type including an adapter
nose with a transverse key bore therein, a removable point provided
with a socket which receives the nose to mount the point thereon
and further provided with an opening which is in alignment with the
key bore when the point is in place to define a keyway, and an
elongate key longitudinally movable into and out of the keyway to
hold the point in place, the key being provided on one surface with
a lock recess that is within the nose when the key is in place and
that is engageable by a detent to limit longitudinal movement of
the key, the combination of:
a passage in the adapter nose that has a communication with said
key bore at a point facing the lock recess when the key is in place
and which has a transverse dimension at such point of communication
that is greater than the key bore width;
upper, lower and side surfaces at said point of communication that
form a cage therebetween that opens toward the key bore;
a lock roller disposed within said cage that is restricted from
lateral and longitudinal movement relative to the key by said cage
surfaces, said lock roller being rotatable about an axis transverse
to the key bore and being movable toward and away from the key
bore, said lock roller having a lateral dimension greater than the
width of the key bore to be limited in movement toward the bore,
said roller defining a curved surface that extends into the key
bore when the roller has moved toward the bore and serves as a
detent engageable with the lock recess; and
a resilient plug disposed in said passage on the side of said lock
roller opposite said key bore, said plug biasing said lock roller
toward said key bore, both said plug and said lock roller being
assembled into position by insertion through said passage;
said lock roller being engageable by the key as it is moved into
and out of said keyway to be rotated about said axis and moved away
from the key bore.
2. The combination of claim 1 wherein the passage is in a plane
parallel to and spaced from the plane of the key bore; and there is
an opening leading from said passage to the key bore, which opening
defines the cage; and the plug is disposed in the passage.
3. The combination of claim 2 wherein the roller is disposed
approximately on the vertical and horizontal center lines of the
nose and point.
4. The combination of claim 3 wherein the key bore extends entirely
through the adapter and the point is provided with openings at both
ends of the key bore to define a continuous keyway, said keyway
being straight sided so that the key can be removed or inserted
from either direction.
5. The combination of claim 1 wherein the passage is transverse to
and extends partially into the key bore and extends entirely
through the nose; and the plug comprises a strip extending along
the side of said passage opposite from the keyway; and there is a
generally U-shaped saddle fixed to said strip near its center and
facing the keyway, said saddle and the walls of said passage
together receiving and defining the cage for the roller.
6. The combination of claim 1 wherein the passage extends entirely
through the nose and is parallel to, in communication with and of
greater lateral width than the key bore; and there is an insert
disposed in and substantially filling said passage, which insert is
provided with a pocket in the face thereof that is opposite from
the key bore and an opening leading from the pocket toward the key
bore, which opening defines the cage; and the resilient plug is
received in said pocket.
7. The combination of claim 1 wherein the passage comprises a
pocket in one surface of the nose which is in communication with
and of greater lateral extent than the key bore and which is
covered by an overhanging portion of the point when the point is in
place; and the plug is received in the pocket at the end thereof
opposite from the key bore; and the roller is received in the
pocket between the plug and key bore, the side and bottom walls of
the pocket serving with the overhanging portion of the point to
define the cage.
8. The combination of claim 1 wherein the key bore comprises
outwardly opening portions of circular cross section on opposite
sides of the nose; and the point is provided with circular openings
which are in alignment with respective bore portions when the point
is in place to define opposite keyways; and there are a pair of
cylindrical keys removably received in respective keyways, each of
the keys being provided near its inner end with a circumferential
groove which defines the lock recess; and the nose is provided with
a pair of passages associated with and spaced from respective key
bores; and there is a pair of plugs received in respective
passages; and there are openings leading from said passages to
respective keyways, said openings defining two cages; and there are
two rollers, one received in each cage to be engageable with the
circumferential groove of the associated key.
9. A roller lock arrangement for a digging tooth assembly of the
type including an adapter nose with a transverse key bore, a point
which has a socket that receives the nose and which is provided
with an opening that is in alignment with the key bore when the
point is in place to define a keyway, and an elongate locking key
that is longitudinally movable into and out of the keyway and that
is provided intermediate its ends with a recess that is within the
nose when the key is in place and that is adapted to receive a
detent to hold the key against longitudinal movement, said lock
arrangement comprising:
a passage in the nose that is in a plane parallel to and spaced
from the key bore; an opening in the nose that leads from the
passage and extends into the key bore and that has an axis
transverse to and of greater lateral extent than the key bore; a
lock roller freely disposed in said opening to be rotatable about
said opening axis, the peripheral walls of said opening defining a
cage which limits lateral and longitudinal movement of the roller
relative to the key, the roller being movable into and out of the
opening through the passage and being of greater lateral extent
than the keyway so that it cannot move out of the opening into the
key bore; and a separate resilient bias means that is movable into
and out of the passage and that is engageable with the roller to
bias the roller toward the key bore, the roller being rotatable
about said axis notwithstanding engagement with the bias means, the
roller presenting a curved surface which extends into the key bore
when the roller has been moved toward the key bore and which serves
as a detent engageable with the lock recess.
Description
Digging teeth assemblies for large excavating machines generally
comprise an adapter that is fitted to or formed with the lip of the
bucket and is provided with a forwardly extending wedge-shaped
nose, and a replaceable tooth point provided with a rearwardly
facing wedge-shaped socket that receives the nose. The point and
adapter nose are provided with vertical or horizontal transverse
openings which extend wholly or partially therethrough and are
aligned when the point is in place to define a keyway. A key is
removably received in the keyway to hold the point on the
adapter.
It is generally necessary to provide some sort of lock to hold the
key against axial or longitudinal movement out of the keyway, and
many forms of locks have been tried. One well-known type includes a
rubber plug mounted in the adapter nose and a metal member wholly
or partially embedded in the plug to define a detent which is
engageable with a recess in the key when the key is in place, the
plug serving to resiliently bias the detent toward the key. While
this sort of lock is generally satisfactory, it is difficult to
construct a lock of this type that will function satisfactorily
after repeated uses. A particular problem in this regard is that
the key must be driven past the detent as it is inserted and
removed, and this results in a considerable shear force parallel to
the direction of movement of the key. This force tends to twist the
plug and pull it into the keyway unless special shoulders or some
other expensive expedient are provided to hold the plug in place in
the adapter nose, and it also results in undue wear. Also, in some
locks of this type it is not possible or convenient to provide for
inserting the key from either side.
SUMMARY OF THE INVENTION
It is the general purpose of this invention to provide a roller
lock for a digging tooth assembly in which the detent element that
engages the key is a roller that is mounted in a cage to be held
against longitudinal or lateral movement with respect to the key
while being freely rotatable on a transverse axis to take up the
aforementioned shear force and to be movable toward and away from
the key so that the key can be driven past. The roller is biased
toward the key by a rubber backup plug or other spring means which
bears against the roller but is not fastened to it as has been the
case with prior locks so that the roller remains free to
rotate.
It is the object of the invention to provide several species of a
lock arrangement of this roller type which are highly effective and
readily adaptable to various sizes of tooth assemblies while still
being relatively simple, inexpensive and easy to use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view in cross section showing a digging tooth
assembly incorporating one embodiment of the invention, the view
being taken through the plane 1--1 shown in FIG. 2,
FIG. 2 is a view in cross section of the embodiment of FIG. 1 taken
through the plane 2--2 shown in FIG. 1,
FIG. 3 is another view in cross section of the embodiment of FIG. 1
which is taken through the plane 3--3 shown in FIG. 1,
FIG. 4 is a view in cross section of a second embodiment of the
invention taken through the plane 4--4 shown in FIG. 5,
FIG. 5 is a view in cross section of the embodiment of FIG. 4 taken
through the plane 5--5 shown therein,
FIG. 6 is a view in cross section of a third embodiment of the
invention taken through the plane 6--6 shown in FIG. 7,
FIG. 7 is a view in cross section of the embodiment of FIG. 6 taken
through the plane 7--7 shown therein,
FIG. 8 is a view in cross section of a fourth embodiment of the
invention taken through the plane 8--8 shown in FIG. 9,
FIG. 9 is a view in cross section of the embodiment of FIG. 8 taken
through the plane 9--9 shown therein,
FIG. 10 is a view in cross section of a fifth embodiment of the
invention taken through the plane 10--10 shown in FIG. 11, and
FIG. 11 is a view in cross section of the embodiment of FIG. 10
taken through the plane 11--11 shown therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiment of the invention shown in FIGS. 1-3 is particularly
preferred for teeth in the range of three to eight inches in width.
The overall construction of the tooth assembly shown is generally
conventional and it includes an adapter that is designated by the
reference numeral 1. In accordance with usual practice the adapter
1 can be formed on or fastened to the lip of a bucket or other
digging implement, and depending on the size of the teeth the
adapter 1 might itself be a multi-part assembly. In any event, the
adapter 1 is provided at its forward end with a generally
wedge-shaped nose 2 which receives a tooth point as will be
described. The forward end of the nose 2 is provided with central,
upper and lower recesses 3, and the upper and lower wedge surfaces
of the nose 2 are provided with spaced, parallel fitup strips 4
which define the surfaces that actually bear against facing
surfaces of the tooth point. Similar strips 4' are provided on the
sides of the nose 2, and these define the surfaces that actually
bear against the facing side surfaces of the tooth point. As can
best be seen in FIG. 3, the strips 4 on the upper surface of the
nose 2 are slightly angled downwardly from the axial center line of
the adapter 1 to the outside and the strips 4 on the lower nose
surface are angled upwardly from center to outside, this slight
angularity serving to help in taking up side loads during digging.
The use of the fitup strips 4, 4' is particularly advantageous in
that they provide a conveniently machinable set of surfaces for
insuring a tight fit of a point on the adapter 1.
The tooth point is designated generally by the reference numeral 5,
and it is provided with a rearwardly facing generally wedge-shaped
socket 6 which receives the nose 2 with a tight wedge fit to mount
the point 5 on the adapter 1, the upper and lower walls of the
socket 6 engaging the faces of the strips 4. Near the forward end
of the socket 6 there are upper and lower bosses 7 which are
received in the recesses 3, this arrangement providing conventional
flat surfaces to help in taking beam loads.
The nose 2 is provided with a vertical key bore 8 of rectangular
cross section which extends completely therethrough, and the tooth
5 is provided with upper and lower key openings 9 which are of the
same general size and which are in alignment with the bore 8 when
the point 5 is in place, the bore 8 and openings 9 together
defining a vertical keyway that extends entirely through the tooth
assembly. An elongated metal key 10 of generally rectangular cross
section is received in the keyway thus formed, and serves to hold
the point 5 in place on the adapter 1. The key 10 has a tapered end
11 which is intended to be inserted into the keyway first, but the
keyway is straight sided so that the key 10 can be inserted either
from above or from below. The forward face of the key 10 is
provided with a transverse groove 12 of substantially circular
cross section at about its midpoint, the groove 12 being engageable
with a lock roller as will be described. The side walls of the
adapter key bore 8 are preferably relieved along the curved lines
13, this configuration serving to define short ledges 14 at
approximately the level of the groove 12, and the rear wall of the
bore 8 is preferably relieved at 15.
The nose 2 is provided with a second vertical passage 16
therethrough which is located forwardly of the bore 8 and which
receives a blocklike, resilient compressible natural or synthetic
rubber backup plug 17. The plug 17 does not quite extend to the
ends of the passage 16, and its free size is such that it must be
compressed slightly when it is inserted in the passage 16 so that
it will remain in place as shown with a friction fit. An opening 18
extends between the bore 8 and passage 16 and defines a
rectangular, open-ended cage within which there is a cylindrical
metal lock roller 19 which is disposed parallel to and facing the
key groove 12 to be engageable therewith. The dimensions of the
roller 19 are only slightly less than those of the cage 18 so that
the roller 19 is held against substantial longitudinal movement
(movement up and down as seen in FIG. 1) or lateral movement
(movement up and down as seen in FIG. 2) with respect to the key
10. The roller 19 is, however, free to rotate about its own axis,
which is transverse to the key 10 and parallel to the groove 12,
and is also free to move toward and away from the key 10 through
the open front and rear ends of the cage 18. The plug 17 bears
against the forward side of the roller 19 and urges it to the rear
or into engagement with the groove 12, but does not prevent the
roller 19 from rotating.
When the parts are assembled as shown in FIGS. 1-3, the roller 19
is received in the groove 12 to be engaged with the key 10 to hold
the same against longitudinal movement in either direction. This is
not a load engagement, however, and the primary load of holding the
point 5 on the adapter 1 is taken by the key 10 during working. The
roller 19 is approximately directly on both the horizontal and
vertical center lines of the assembly to insure uniform
distribution of forces.
To remove the point 5, the key 10 is driven upwardly or downwardly
as seen in FIG. 1. During this action, the key 10 exerts a shear
force on the roller 19, but this is taken up by a slight rotation
of the roller 19 and does not cause any particular problems. If the
roller 19 were embedded in or fastened to the plug 17 as in older
locks, however, this force would tend to rip it free or pull the
entire plug 17 into the bore 8. When the key 10 is reinserted it
exerts a similar shear force in the opposite direction, but this is
again taken up by rotation of the roller 19.
When the key 10 is removed, the plug 17 moves the roller 19 to the
right as seen in FIG. 1, but it cannot come out of the cage 18
because it comes against the ledges 14. Thus, there is no danger of
the roller 19 falling out and being lost during replacement of a
tooth point. The roller 19 is of course inserted into the cage 18
during initial assembly through the larger passage 16, which is as
wide as the roller 19, and the plug 17 is inserted after the roller
19 is in place. It should be appreciated that the ledges 14 are in
essence the result of the fact that the width of the bore 8 is less
than that of the cage 18. That the ledges 14 are found only at
about the center of the cage 18 in the preferred embodiment is due
to the relieving of the side walls of the bore 8 along the lines
13.
The embodiment of the invention shown in FIGS. 1-3 provides an
extremely effective lock for the key 10, and is also highly
desirable because it is relatively simple to manufacture and has a
minimum number of parts. The bore 8 and passage 16 and the cage
opening 18 are all relatively easy and inexpensive to form during
manufacture of the adapter 1, and both the plug 17 and roller 19
are easy to make and assemble. None of the parts need be made to
extremely close tolerances or substantially machined.
The embodiments of the invention shown in FIGS. 4 through 9 are
quite similar to the embodiment of FIGS. 1-3 and operate in much
the same way but they differ in manufacturing details. Since the
basic elements of the tooth assembly are similar to those of the
embodiment of FIGS. 1-3, like reference numerals have been used to
refer to like parts, and different numbers have been used only for
the lock rollers, backup plugs and associated elements.
Turning first to the embodiment of FIGS. 4 and 5, in this
embodiment there is a horizontal transverse passage 20 which
extends entirely through the nose 2 and is generally oval in cross
section. A suitably formed compressible rubber strip 21 is mounted
in the forward side of the passage 20 and extends along
substantially the entire length thereof, and is provided with a
generally U-shaped metal saddle 22, which is vulcanized or
otherwise affixed to the rear surface of the strip 21. The saddle
22 retains a cylindrical roller 23 and, with the upper and lower
walls of the passage 20, serves to define a cage which allows the
roller 23 to rotate about a transverse axis and move toward and
away from the key 10 but holds it against longitudinal or lateral
movement with respect thereto. It is important to note that
although the saddle 22 is affixed to the rubber strip 21 to help
form the cage, the roller 23 is still free to rotate about its own
axis with the same effect as the roller 19 in the embodiment of
FIGS. 1-3. In this embodiment, the rear end of the passage 20
extends into the bore 8, and this defines curved ledges 24 which
limit rearward movement of the roller 23. The advantage of this
embodiment is that only the single passage 20 need be formed in the
nose 2 as opposed to the passage 16 and cage 18 of the embodiment
of FIGS. 1-3, and the saddle 22 can be fabricated separately and
fastened to the strip 21 before the latter is inserted. Again, the
key 10 can be inserted or removed in either direction.
In the embodiment of FIGS. 6 and 7, there is a single vertical
passage 25 through the nose 2 which is forward of, extends into,
and is of greater width than the bore 8. A metal insert 26 is
received in and substantially fills the bore 25 with a relatively
close fit. The rear surface of the insert 26 is channeled along its
entire vertical length so that it establishes the forward part of
the bore 8 and receives the forward part of the key 10. The forward
wall of the insert 26 is recessed to define a pocket 27 which
tightly receives a backup plug 28. An opening 29 is cut
transversely through the insert 26 and communicates with the pocket
27 and the forward portion of the bore 8 established by the
channel. A roller 30 is received in the opening 29, and the upper
and lower walls of the opening 29 and the nose surfaces at the ends
thereof together define a cage. The opening 29 is horizontally
elongated to present rear curved ledges 31 on opposite sides of the
channel which limit rearward movement of the roller 30 and forward
curved ledges 32 on opposite sides of the pocket 27 which limit
forward movement. The advantage of this embodiment is that it is
necessary only to provide the single straight walled passage 25 in
the adapter 1, and the insert 26 can be separately formed and
machined. The key 10 can be inserted or removed in either
direction.
In the embodiment of FIGS. 8 and 9, instead of a passage running
entirely through the nose 2, there is a pocket 33 formed on the
upper surface thereof which receives a compressible backup plug 34
and a roller 35. In this embodiment, the groove 12 of the key 10 is
located higher to put it at the higher level of the roller 35, and
the side walls of the bore 8 are shaped to define curved ledges 36
which limit rearward movement of the roller 35. Also, the upper
portion 37 of the tooth 5 that overhangs the pocket 33 serves as
part of the cage for the roller 35. This embodiment functions
generally the same as the previous embodiments, and is very easy to
manufacture, but has one disadvantage in that the locking forces
are not as uniformly distributed about the center line of the
assembly as in the previous embodiments in all of which the rollers
are at the horizontal and vertical center lines. Also, in this
embodiment the key 10 should be driven in from above, but can be
removed in either direction.
The embodiment of FIGS. 10 and 11 is particularly designed for
large teeth where the use of a single key is not feasible. In this
embodiment, there is a transverse key bore 38 of circular cross
section, somewhat enlarged in the center, which extends through the
adapted nose 2 to define opposite, outwardly opening portions 38',
and the tooth point 5 is provided with circular side openings 39
which are aligned with respective end portions 38' of the bore 38
when the tooth point 5 is in place to define two opposite keyways.
In each keyway there is received a headed cylindrical pin or key
40, the two keys 40 together serving to hold the tooth point 5 on
the adapter 2. Each key 40 has a circumferential lock groove 41
near its inner end.
Forwardly of the bore 38, the adapter nose 2 is provided with
opposite pockets or passages 42, and each pocket 42 receives a
rubber backup plug 43 which is slightly compressed to be held in
place. A cage opening 44, like the opening 18, leads rearwardly
from each passage 42 to the bore 38 and receives and serves as a
cage for a roller 45. The rollers 45 engage the grooves 41 to hold
the keys 40 in place, and as in the case of the previous
embodiments, the rollers 45 are held in the cages 44 against
lateral or longitudinal movement relative to the keys 40 but are
free to move toward and away from the keys 40 and are also free to
rotate about axes transverse to the keys 40 to take up shear forces
exerted by the keys 40 as they are driven past during insertion or
as they are removed. The cage openings 44 are transverse to and
extend into the circular bores 38', and this defines upper and
lower retaining ledges 46 for the rollers 45. Advantages of this
embodiment are its suitability for larger teeth, ease of
manufacture, and the fact that the cylindrical keys 40 with the
circumferential grooves 41 need have no particular orientation
since a portion of the recess defined by the grooves 41 will always
appear on the faces of the pins 40 that face the rollers 45.
Although it is preferred in this embodiment to have the continuous
bore 38, it would be possible to drill separate bores only
partially into each side of the nose 2.
In each of the embodiments shown and described, the basic structure
and operation is the same in that there is a roller which is
engageable with a recess in a key to hold the key in place, and the
roller is in a cage to be freely rotatable about a transverse axis
to take up shear forces which occur as the key is inserted or
removed. Although the embodiments shown represent several preferred
manners to effect this desired result, it will be obvious that
variations and modifications might be possible without departure
from the scope of the invention. A ball roller might be substituted
for the cylindrical roller shown, with a spherical recess then
replacing the groove recess 12 and a circular cage replacing the
rectangular cages shown, and this would still provide the desired
rotatability about an axis transverse to the key. Further, an
appropriately shaped leaf spring or other bias means might be
substituted for the rubber plug to bias the roller toward the key.
In the embodiment of FIGS. 1-3, it would be possible instead of
providing the throat or cage opening 18 to provide a circular cross
bore extending entirely through the adapter nose 2 and to replace
the roller 19 with a pin approximately of the same length as the
width of the nose 2 which extends entirely therethrough. It is not
absolutely necessary in any of the embodiments to have a keyway
running entirely through the assembly or to have a key that can be
inserted or removed in either direction. In view of the many
possible modifications, it is not intended that the invention be
limited by the showings herein or in any other manner except as may
specifically be required.
* * * * *