U.S. patent application number 09/949490 was filed with the patent office on 2002-05-02 for tamping tool.
This patent application is currently assigned to H.G. Specialty Tool, Inc.. Invention is credited to Gevik, Glenn, Henricks, John Edward.
Application Number | 20020051682 09/949490 |
Document ID | / |
Family ID | 26925074 |
Filed Date | 2002-05-02 |
United States Patent
Application |
20020051682 |
Kind Code |
A1 |
Gevik, Glenn ; et
al. |
May 2, 2002 |
Tamping Tool
Abstract
The present invention includes a tamping tool having a main
shaft body with an end portion having a tongue section and a
tamping pad having a groove for receiving and engaging the tongue
section. The tamping pad preferably includes an abrasive material
along a tamping edge. A weld bead is used to secure the tongue
section with the groove.
Inventors: |
Gevik, Glenn; (Duluth,
MN) ; Henricks, John Edward; (St. Germain,
WI) |
Correspondence
Address: |
KINNEY & LANGE, P.A.
THE KINNEY & LANGE BUILDING
312 SOUTH THIRD STREET
MINNEAPOLIS
MN
55415-1002
US
|
Assignee: |
H.G. Specialty Tool, Inc.
1578 1/2 Highway 155
St. Germain
WI
54558
|
Family ID: |
26925074 |
Appl. No.: |
09/949490 |
Filed: |
September 7, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60231385 |
Sep 8, 2000 |
|
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Current U.S.
Class: |
404/133.05 |
Current CPC
Class: |
E01B 2203/12 20130101;
E01B 27/16 20130101 |
Class at
Publication: |
404/133.05 |
International
Class: |
E01C 019/30 |
Claims
1. A tamping tool comprising: an integrally formed main shaft
having at one end a tongue section; and a tamping pad having a
groove configured to receive and engage the tongue section, the
tamping pad having a lower tamping edge and wherein at least the
lower tamping edge is made of an abrasive material.
2. The tamping tool of claim 1 wherein the tongue section is of a
dovetail configuration and the groove is of a configuration to
receive the dovetail configured tongue section.
3. The tamping tool of claim 1 wherein the abrasive material is a
nickel chromium alloy.
4. The tamping tool of claim 1 wherein the abrasive material
comprises tungsten carbide, chrome carbide or tantalum carbide.
5. The tamping tool of claim 1 wherein the tongue section is
retained within the groove by a weld.
6. The tamping tool of claim 5 wherein the weld is a 312 alloy.
7. A method of attaching a tamping pad to a tamping tool
comprising: providing a shaft having at one end a tongue section;
providing a tamping pad having a groove configured to receive and
engage the tongue section; engaging the groove by sliding the
tongue section within the groove; and retaining the tongue section
within the groove.
8. The method of claim 8 and further including providing a weld
bead.
9. The method of claim 8 and wherein the weld is a 312 alloy.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The present application claims priority from Application
Serial No. 60/231,385 filed on Sep. 8, 2000, entitled "TAMPING
TOOL".
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to ballast tamping
equipment. More specifically, the present invention relates to a
tamping tool for mounting onto a ballast tamping apparatus for
tamping ballast on railway lines, crushing minerals, or for other
similar purposes.
[0003] A tamping apparatus is typically used to repair and correct
a ballast of a roadbed around and beneath one or more railroad ties
so that the road bed can uniformly support the passage of a
railroad train. The tamping apparatus may be designed to move along
the road bed and at each tie to force at least one tamping tool
that is included as part of the tamping machine into the ballast.
The tamping tool is generally attached to a reciprocatory and
vibratory drive of the tamping apparatus, and then immersed into
the ballast bend. The tamping tool is then vibrated and moved
toward the tie in unison to compact the ballast under the tie and
provide a firm foundation around and beneath the tie. As a result
of tamping the ballast, the rail road bed is capable of providing a
solid foundation for a train passing over the rail road bed.
[0004] Nevertheless, the use of one or more tamping tools as part
of a ballast tamping apparatus still poses several challenges. For
example, ballast materials like sand, slag, gravel or cinders, are
highly abrasive and typically wear down a leading edge of the
tamping tool during tamping operations. As a result, the leading
edge of the tamping tool or the entire tamping tool must be
repaired, replaced and/or rebuilt after a certain operating
time.
[0005] Unfortunately, tamping tools are often manufactured from
heavy metals that make removal of the tamping tools cumbersome and
time-consuming. In addition, the tamping apparatus may contain 8 to
16 tamping tools, which further adds to the degree of complexity
when replacing tamping tools. Furthermore, a lack of facility to
quickly replace the worn tamping tool may also be a problem when
attempting to repair the tamping tool since the tamping tool must
typically be removed from the tamping apparatus.
[0006] As an alternative, the tamping tool may include a detachable
tamping blade that may be removed when worn. Nonetheless, mere
removal of the detachable tamping blade is not simple, since the
tamping blade may have been bolted or otherwise attached to the
tamping tool, and may require cutting the detachable tamping blade
off of the tamping tool. Cutting the detachable tamping blade off
of the tamping tool typically involves special equipment and time
that can affect efficient operation of the tamping apparatus. In
addition, the detachable tamping blade may have been irregularly
worn during operation which could negatively impact other parts of
the tamping tool and therefore, necessitate replacement of the
entire tamping tool.
[0007] Tamping tools may also be manufactured with detachable
tamping blades that include one or more inserts along a leading
edge of the tamping blade to increase the life of the tamping
blades. Such inserts may be formed from high chromium-steel braze
or a tungsten carbide insert. However, the inserts may also undergo
abrasion and/or undercutting such that the inserts fall out.
Consequently, frequent replacement of the inserts may be required
which results in loss of time or the use of special equipment. If
the tamping blades include inserts that do not extend across an
entire leading edge of the tamping blade insufficient protection of
the tamping blade during lateral movement of the tamping tool
through the ballast may irregularly wear out the leading edge, and
require replacement of the entire tamping blade or tamping tool.
Therefore, an urgent need currently exists to manufacture a tamping
tool that includes a tamping blade, such that the tamping blade has
a prolonged useful life. Furthermore, there exists an urgent need
to manufacture a tamping tool that includes a tamping blade, such
that the tamping blade may be easily removed in a minimal amount of
time using minimal equipment.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention includes a tamping tool having a main
shaft with an end portion with a tongue section. A tamping pad is
attached to the end portion and has a groove for receiving and
engaging the tongue section. The tamping pad includes an abrasive
material along a tamping edge. A weld bead is used to secure the
tamping pad to the main body shaft along with the engagement of the
tongue section and groove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an exploded perspective view of the present
invention FIG. 2 is an exploded perspective view of another
embodiment of the present invention.
[0010] FIG. 3 is a sectional view taken along the line 3-3 in FIG.
5.
[0011] FIG. 4 is a side elevational view of the embodiment of FIG.
1.
[0012] FIG. 5 is a front elevational view of the embodiment of FIG.
1.
DETAILED DESCRIPTION
[0013] A tamping tool having a generally rectangular shaped
cross-sectional configuration is generally depicted at 10 in FIG.
1. Alternatively, the tamping tool as generally shown at 10a in
FIG. 2 includes a cylindrical mid portion 16a a frusto-conical
upper portion 14a and the tamping pad 20. While specific tamping
tools 10 and 10a are generally depicted in FIGS. 1 and 2,
respectively, it will be understood that the tamping tools having
cross sectional configuration of any form are within the present
invention. Like reference characters will be used to indicate like
elements throughout the Figures.
[0014] The tamping tool 10 of FIG. 1 includes a shaft 12 having an
upper portion 14, a middle portion 16, a lower portion 8 and a
tamping pad 20. The upper portion 14 of the shaft 12 further
includes transversely disposed mounting apertures 21. The mounting
apertures 21 facilitate connecting the tamping tool 10 to a tamping
apparatus such as a Jackson tamping apparatus (not shown).
[0015] The tamping tool 10a of FIG. 2 has a threaded longitudinal
mounting aperture 15 that is used to attach the tamping tool 10a to
a tamping apparatus (not shown), such as a Camron tamping
apparatus. A bolt (not shown) is used to attach the tool 10a to the
tamping apparatus (not shown) by engaging the aperture 15.
[0016] The tamping pad 20 has a wear resistant tamping edge portion
22 and is detachably attached to the lower portion 18. The pad 20
is attached in a manner that withstands continuous impacts that the
tamping tools 10 and 10a receive during use. For attachment to
either the shaft 10 or 10a, the tamping tool 20 includes a groove
24 that engages a tongue section 26 of the lower portion 18. The
tongue section 28 includes a front face surface 32 that starts at
an upper shoulder 33 and ends at a lower edge 34. The tongue
section 26 is further defined by inwardly projecting side edges 27
and 28 that form an acute angle with the face surface 32, as best
illustrated in FIG. 3. Shoulders 29 and 30 are disposed parallel to
the face edge 32 and conjoin with side edges 27 and 28,
respectively. The groove 24 of the tamping portion 20 includes a
groove face surface 36 for engaging the face surface 32 of the
tongue section. Sidewalls 37 and 38 of the groove 24 face and are
disposed at an incline to engage the side edges 27 and 28 of the
tongue section 28, respectively. The shoulders 29 and 30 are
engaged by wall portions 39 and 40 of the tamping portion 20. In
essence, the engagement between the lower portion 18 of the shaft
12 and the tamping pad 20 is a dovetail interlocking engagement. It
is preferred that the groove has sides that incline toward each
other so that when the tongue is slid within the groove, the tongue
is retained against lateral forces that are created during the
tamping operation. Of course, the tamping pad abuts against the
shoulder 34 so that the tongue section does not move any further
along the groove due to vertical forces that are created during the
tamping operation.
[0017] The lower portion 18 further includes a brace section 36 as
best illustrated in FIG. 4 that provides support to the tongue
section when attached to the tamping pad 20.
[0018] The shaft 12 of the tamping tool 10 or 10a may be formed
from carbon steel of suitable hardness, for example, AISI/1010
through 1045 carbon steel or an alloy steel like AISI/8620 or
AISI/4140. As an example, the shaft 12 may be formed from an AISI
4140 alloy steel which is a superior material of suitable hardness
that significantly enhances and prolongs the useful life of the
tamping tool 10 or 10a. In another example, the shaft 12 may be
formed from an AISI 1045 carbon steel that also enhances and
prolongs the useful life of the tamping tool 12.
[0019] When the shaft is made from AISI 4140 alloy steel, the shaft
12 is typically derived from a cold-rolled, air machined, 3-inch
thick section of AISI 4140 steel. In addition, AISI 4140 alloy
steel may be characterized as a medium wear-resistant, high tensile
strength, high-carbon alloy.
[0020] The tamping pad 20 includes a body of hard wear-resistant
material having an upper surface 72 and a lower surface 74,
respectively. The upper surface 72 of the tamping pad 20 abuts the
shoulder 34 of the shaft 12. The tamping pad 20 further includes
first and second major opposed surfaces 76 and 78, respectively.
The distance between first and second major opposed surfaces 76 and
78 is preferably at least about 1-inch in thickness. Prior art pads
are significantly thinner. In addition, the approximate distance
between upper surface 72 and lower surface 74 is at least about 4
inches. The tamping pad 20 also includes opposed outside surfaces
80 and 82. Preferably, the approximate distance between opposed
outside surfaces 80 and 82 is at least 4 inches in length.
[0021] The tamping pad 20 is generally formed from a hard
wear-resistant material, such as hardened steel or a metal carbide,
such as tungsten carbide, titanium carbide, chrome carbide or some
other hard material that is preferably both wear-resistant and
abrasion resistant. In addition, the tamping pad 20 may include one
or more additional layers of hard wear-resistant material. The
additional layers may cover a partial or entire surface of the
tamping pad when practicing the present invention. As an example,
an additional layer of the hard wear-resistant material may merely
cover the lower surface 74 of the tamping pad 20 for further
protection since the lower surface 74 comes into contact with the
ballast, gravel or other hard material that is being compacted. As
an another example, the additional layer of the hard wear resistant
material may cover the entire surface of the tamping pad, including
the lower surface 74.
[0022] When the lower surface 74 of the tamping pad 20 is covered
with an additional layer of hardened material, the additional layer
(not shown) may be also be formed from hardened steel or from a
metal carbide, such as tungsten carbide, titanium carbide, tantalum
carbide or some other hard material that is wear-resistant and
abrasion resistant.
[0023] Preferably, the tamping pad 20 is formed from a nickel
chromium alloy that has excellent abrasion resistance. As an
example, Type I or Type IV regular ASTM A 532 I-A nickel chromium
alloy may be used to form the tamping pad 20 of the present
invention. An example of a chemical composition for Type I regular
ASTM A 532 I-A nickel chromium alloy is listed in Table 1
below:
1 TABLE 1 CHEMICAL WEIGHT PERCENT* Total Carbon 3.0-3.6 Silicon 0.8
maximum Manganese 1.3 maximum Sulfur 0.15 maximum Phosphorous 0.30
maximum Nickel 3.3-5.0 Chromium 1.4-4.0 *based on a total weight of
the nickel chromium alloy
[0024] Thus, the present invention also includes a method of
attaching the tamping pad 20 to the shaft 12. The method of
attaching the tamping pad 20 includes inserting the tongue section
28 into the groove 24, as shown in FIGS. 1 and 2 until the tamping
pad is attached to the shaft 12 as shown in FIGS. 4 and 5. It
should be noted that the tamping pad 20 abuts the lower horizontal
shoulder 34 of the shaft 12 which stops the tamping pad's 20 travel
along the tongue section 28 of the shaft 12.
[0025] The tamping pad is retained in place by providing a weld
bead 29 of 312 type alloy to secure the tamping pad 20 to the end
of the shaft 12, in conjunction with the engagement of the tongue
section with the groove 24. The weld bead 29 is preferably placed
along the edges of all outer surfaces of the pad 20 and the end
portion 18 that meet. Alternatively, a bolt (not shown) may be used
to retain the connection.
[0026] To remove the tamping pad 20 from the shaft 12, the shaft 12
and the tamping pad 20 may be heated to remove the weld. Once the
weld has been removed, the tamping pad 20 can be simply slid off of
the tongue section 28 and disconnected from the shaft 12.
Therefore, the method of attaching the tamping pad 20 to the shaft
12 of the tamping tool 10 using a dovetail interlocking mechanism
permits quick and easy attachment and detachment of the tamping pad
20 to and from the tamping tool 10. In addition, the dovetail
interlocking mechanism permits simple and rapid attachment and
detachment of tamping pads to tamping tools when the tamping pads
are formed from materials that are unable to withstand welding
temperatures.
[0027] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention.
* * * * *