US20040118021A1

US20040118021A1 - Longitudinal orientation of a retainer for a bucket tip

Info

Publication number: US20040118021A1
Application number: US10/328,342
Authority: US
Inventors: Williams Renski
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2002-12-23
Filing date: 2002-12-23
Publication date: 2004-06-24

Abstract

A retainer for removably attaching a ground engaging tooth to an adapter. The retainer comprises a cylindrical steel member adapted to fit into a pocket defined in the outside surface of the adapter and an opening defined in an inside surface of the tooth. The retaining pin is further held in a locking position by a secondary retainer made of spring steel.

Description

TECHNICAL FIELD

The present invention relates generally to an excavating bucket and more specifically to a retention arrangement for a ground engaging tooth and adapter.

BACKGROUND

Excavating apparatus is commonly equipped with a bucket that serves for accepting and moving a discreet quantity of material, such as soil, rock, and gravel. The bucket is typically controllably and pivotally mounted on one or more arms, enabling an operator to control the bucket. One, or preferably more teeth, extending from the bucket in such a way as to engage and break loose the material as the bucket is driven into the material. Because of the varying characteristics of the materials upon which excavating apparatus is used, it is common to provide these bucket tips as tooth subassemblies.

These tooth subassemblies, typically are comprised of a tooth mounted upon an adapter that may be selectively secured to the bucket. As the bucket tips are the primary material engaging elements, they are subjected to a high degree of wear. This wear reduces the functionality of the bucket tips over time necessitating their occasional replacement. One of the more successful methods of assembling a bucket tip to the tooth sub-assembly has been to provide a bucket tip having a rearward facing opening designed to cooperatively accept a mounting protrusion from the tooth adapter base. This mounting protrusion typically provides sufficient structural support to ensure that the bucket tip remains generally in the appropriate alignment with respect to the tooth subassembly.

In order to retain the bucket tip on the tooth adapter base, openings are provided for accepting a securing means through the bucket tip and the adapter. Typically a retaining pin is oriented transversely though the bucket tip the adapter base to secure the tip. Depending on the type of digging operation being performed, the retaining pin may be subject to high shear loads at the intersection between the tip and adapter. During digging operations such as back-dragging, forces tend to pull the tip from the adapter, creating abnormally high shear loads on the pin. Failure of the pin will cause loss of the tip.

It is desirable to provide a tip and adapter assembly that is capable of overcoming one or more of the above stated problems.

SUMMARY OF THE INVENTION

A ground engaging tooth having a central axis, a mounting end portion and a ground engaging portion. The tooth includes an outside surface and an inside surface. A retainer opening extends from the outside surface to the inside surface and is oriented substantially parallel to the nose surface. An access bore is defined in the inside surface and configured to lock a secondary retainer with a retainer pin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an adapter having a tooth position on and mechanically retention system the present invention. [0007]
FIG. 2 is an exploded view of the tooth, adapter and retention system as shown in FIG. 1. [0008]
FIG. 3 is a cross-sectional view of one embodiment of the retention system taken generally along line [0009] 3-3 of FIG. 1.
FIG. 4 is a cross-sectional view of another embodiment of retention system taken generally along line [0010] 3-3 of FIG. 1.
FIG. 5 is a perspective view of an alternative embodiment of a secondary retainer of the present invention.[0011]

DETAILED DESCRIPTION

Referring to FIGS. [0012] 1-3, a tooth 14 positioned on an adapter 16 for use with an implement bucket (not shown) is illustrated. The adapter 16 is typically secured to a cutting edge of the bucket by welding. The adapter 16 includes a forward tooth mounting portion or nose 18, as best illustrated in FIG. 2. The nose 18 extends along a central axis 22. The tooth 14 is a replaceable ground engaging tool 24, which in this case is a tooth is removably fastened to the adapter 16. The tooth 18 retained on the adapter 14 by a mechanical retention system 26 to be more fully described below.
Referring to FIG. 2, the [0013] nose 18 is generally oriented along the normal direction of working forces exerted on the tooth 14 as it is in working engagement with the ground, and is depicted by arrow 28. The nose 18 includes a blunt abutment surface 30 that is oriented perpendicular to the arrow 28. The blunt surface 30 is configured to receive the loading forces of the tooth 14 caused by earthworking. A plurality of angled surfaces 32 extend rewardly from the blunt surface 30 and radially outward from the central axis 22. The plurality of angled surfaces 32 define a somewhat conical member 34. A retainer pocket 36 is provided in the conical member 34. The retainer pocket 36 having a shape that substantially one half of a cylinder and is oriented longitudinally. The retainer pocket 36 includes a bottom surface 38 and an end abutment surface 40. The retainer pocket 36 is preferably positioned along a side of the nose 18, although may be positioned in any one of the plurality of the angled surfaces 32.
The [0014] tooth 14 includes a front ground engaging portion 42 and a rear mounting end portion 44. The ground engaging portion 42 includes a top surface 46 and a bottom surface 48 that are tapered toward the front and converge to define horizontal edge 50. A pair of side surfaces 48 (one shown) extend between the top 46 and bottom surface 48. The mounting end portion 46 includes an outside surface 50 and an inside surface 52 defining a wall 54 there between. A cavity 56 is defined by the inside surface 52 and configured to snuggly fit over the nose 18 of the adapter 16. The cavity 56 includes an abutment surface (not shown) defined at the bottom of cavity 56. The abutment surface mates with the blunt surface 30 for transferring loads to the adapter 16. A generally rectangular retainer opening 58 is formed in the wall 54 and extends from the outside surface 50 through to the inside surface 52. When the tooth 14 is positioned on the adapter 16 the retainer pocket 36 and the retainer opening 58 align. A retainer pin 60, defining a substantially cylindrical member is inserted into the retainer opening 58 and contacts the bottom surface 38 of the retainer pocket 36.
Referring now to FIGS. 2 and 3, a section view of the [0015] tooth 14 showing the retainer pin 60 positioned in the retainer pocket 36. As illustrated the retainer pin 60 includes a first end 62, a second end 64 and a shoulder portions 66 disposed at each end 62, 64. A recess 68 is defined between the shoulder portions 66. With the pin 60 seated in the retainer pocket 36 a portion of the pin 60 remains in the retainer opening 58 of the tooth 14. Interference of the pin 60 with the retainer pocket 36 and the retainer opening 58 prevents the tooth 14 from being removed from the adapter 16. A secondary retainer 70 engages the pin 60 and the tooth 14 or adapter 16 to hold the pin 60 in the retainer pocket 58.
One embodiment of the [0016] secondary retainer 70 is shown in FIG. 3. The secondary retainer 70 is formed of spring steel or a similar resilient material. The secondary retainer 70 includes a width 72 that is slightly smaller than the recess in the retainer pin 60. With the pin 60 seated in the retainer pocket 36 the secondary retainer fits into a gap 74 defined between the inside surface of the tooth 14 cavity 56 and the adapter 16. The secondary retainer 70 includes a hook portion 76 that engages and holds the retainer pin 60 in place and a bore 78 that can be fastened to either the tooth 14 or adapter 16. An access bore 79 in the tooth 14 aligns with the bore 78 of the secondary retainer 70. A fastener 80 such as a rivet or bolt engages the bore 78.
Referring now to FIG. 5, an alternate embodiment of the present invention is illustrated. In this embodiment the [0017] retainer pocket 36 is wider than the diameter of the retainer pin 60 and the retainer opening 58 aligns partially with retainer pocket 36. The secondary retainer 70′ includes a horseshoe shaped portion 82 and a tab portion 84. The secondary retainer 70′ is installed into the prior to inserting the retaining pin 60. The tab portion 84 of the secondary retainer 70 engages the access bore 79 of the tooth 14 locking the secondary retainer 70 in place. The secondary retainer 70 can be released by depressing the tab portion 84. As the retainer pin 60 is inserted, the pin 60 engages and compresses the horseshoe portion 82. Upon being fully inserted into the retainer pocket 36, the horseshoe portion 82 urges the pin 60 away from the retainer opening 58, thus locking the pin in engaging contact with the tooth 14 and adapter 16.
It should be noted, numerous alternative [0018] secondary retainer 70 embodiments might used without deviating from the scope of the invention.

INDUSTRIAL APPLICABILITY

In operation the [0019] tooth 14 and adapter 16 of the present invention function in a typical fashion. As the implement digs or otherwise applies forces in the normal direction, the abutment surface 56 of the tooth 14 pushes on the blunt surface 30 of the adapter 22. In situations such as back-dragging, forces tend to pull the tooth 24 away from the adapter 16, the retaining pin 60 is compressed between the retainer pocket 36 and the retainer opening 58. Because the steel retainer pin 60 can withstand high compressive loading, it may be smaller than a laterally oriented pin.

List of Elements

Title: Longitudinal Orientation of a Retainer for a Bucket Tip [0020]
File: 01-832 [0021]
[0022] tooth 14
[0023] adapter 16
nose (adapter) [0024] 18 central axis 22
[0025] ground engaging tool 24
[0026] mechanical retention system 26
arrow (direction of forces) [0027] 28
[0028] blunt surface 30
plurality of angled surfaces (nose) [0029] 32
[0030] conical member 34
[0031] retainer pocket 36
bottom surface (pocket) [0032] 38
end abutment surface (pocket) [0033] 40
get [0034] portion 42
[0035] ground engaging portion 42
mounting [0036] end portion 44
top surface (get end) [0037] 46
bottom surface (get end) [0038] 48
pair of side surfaces (get end) [0039] 48
outside surface (mounting [0040] end 50
inside [0041] surface 52
[0042] wall 54
[0043] cavity 56
abutment surface (cavity) [0044] 58
retainer opening (tooth surface) [0045] 58
[0046] retainer pin 60
first end (retainer pin) [0047] 62
second end (retainer pin) [0048] 64
shoulder portions (retainer pin) [0049] 66
recess (retainer pin) [0050] 68
[0051] secondary retainer 70
width (retainer) [0052] 72
gap (tooth and adapter) [0053] 74
hook portion [0054] 76
bore ([0055] secondary retainer 78
access bore [0056] secondary retainer 79
fastener (secondary retainer) [0057] 80
[0058] horseshoe portion 82
[0059] tab portion 84

Claims

What is claimed is:

1. A ground engaging tooth having a central axis, a mounting end portion and a ground engaging portion, said tooth comprising:

an outside surface;

an inside surface having an end abutment surface;

a retainer opening extending from said outside surface to said inside surface, wherein said retainer opening is oriented substantially parallel to said nose surface; and

an access bore is defined in said inside surface, wherein said access bore is configured to permit one of locking and releasing a secondary retainer to and from an engagement position with a retainer pin.

2. The ground engaging tooth of claim 1, wherein said secondary retainer is fixed to one of a tooth or adapter using a rivet.

3. The ground engaging tooth of claim 1, wherein said secondary retainer is fixed to one of said tooth and adapter using a bolt.

4. The ground engaging tooth of claim 1, wherein said secondary retainer is fixed to one of a tooth and an adapter using a tab being defined on said secondary retainer.

5. The ground engaging tooth of claim 1, wherein said secondary retainer is constructed of spring steel.

6. The ground engaging tooth of claim 1, wherein said secondary retainer is configured to urge said retaining pin into a pocket defined between said tooth and an adapter.

7. A retaining apparatus adapted for removably attaching a tooth to an adapter, said apparatus comprising:

a retaining pin configured to fit partially within a retainer pocket defined longitudinally on a surface of said adapter and extend partially into a retainer opening defined in the wall of said ground engaging tooth; and

a secondary retainer configured to fit in a gap defined between an inside surface of said tooth and a nose portion of said adapter, wherein said secondary retainer maintains said retaining pin in a position preventing said tooth from being removed from said adapter.

8. The retaining apparatus of claim 7, including a fastener adapted to attach said secondary retainer to one said tooth and said adapter.

9. The retaining apparatus of claim 8, wherein said fastener is a tab defined on said secondary retainer.

10. The retaining apparatus of claim 8, wherein said fastener is a bolt.

11. The retaining apparatus of claim 8, wherein said fastener is a pin disposed through a bore on said secondary fastener.

12. The retaining apparatus of claim 7, wherein said secondary retainer is constructed of spring steel.

13. The retaining apparatus of claim 7, wherein said secondary retainer is configured to urge said retainer pin into said retainer pocket.