U.S. patent application number 10/653120 was filed with the patent office on 2004-03-04 for piston-rod scraping ring accommodated in a groove in a dashpot cap, and method of inserting such a ring in such a groove.
This patent application is currently assigned to Krupp Bilistein GmbH. Invention is credited to Adrian, Adolf, Nevoight, Andreas.
Application Number | 20040040151 10/653120 |
Document ID | / |
Family ID | 7688830 |
Filed Date | 2004-03-04 |
United States Patent
Application |
20040040151 |
Kind Code |
A1 |
Adrian, Adolf ; et
al. |
March 4, 2004 |
Piston-rod scraping ring accommodated in a groove in a dashpot cap,
and method of inserting such a ring in such a groove
Abstract
A piston-rod scraping ring (7) of elastic material accommodated
in an inward opening groove (9) in a dashpot cap (2) and especially
intended to scrape water and dirt off a piston rod (1). The object
is to allow the ring to be easily inserted into the groove and
secured there until the overall dashpot is assembled. The groove is
accordingly higher at its outer circumference and its inner
circumference (12) is deformed, compressing the rim (8) in
place.
Inventors: |
Adrian, Adolf; (Ennepetal,
DE) ; Nevoight, Andreas; (Hagen, DE) |
Correspondence
Address: |
Max Fogiel
61 Ethel Road West
Piscataway
NJ
08854
US
|
Assignee: |
Krupp Bilistein GmbH
|
Family ID: |
7688830 |
Appl. No.: |
10/653120 |
Filed: |
September 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10653120 |
Sep 2, 2003 |
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10175240 |
Jun 18, 2002 |
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6668452 |
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Current U.S.
Class: |
29/888.044 ;
29/888.049 |
Current CPC
Class: |
Y10T 29/49256 20150115;
Y10T 29/49297 20150115; Y10T 29/49915 20150115; F16F 9/36 20130101;
Y10T 29/49252 20150115; F16F 9/3207 20130101; Y10T 29/49265
20150115 |
Class at
Publication: |
029/888.044 ;
029/888.049 |
International
Class: |
B21K 001/18; B23P
011/00; B23P 015/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2001 |
DE |
101 29 734.3 |
Claims
1. Piston-rod scraping ring (7) of elastic material accommodated in
an inward opening groove (9) in a dashpot cap (2) and especially
intended to scrape water and dirt off a piston rod (1),
characterized in that the groove is higher in the vicinity of its
outer circumference and the rim (8) around the ring is axially
compressed in the vicinity of the inner circumference (12) of the
groove.
2. Method of inserting the piston-rod scraping ring (7) into the
groove (9) in a dashpot cap (2) recited in claim 1, characterized
in that the rim (8), which is intended to occupy the groove (9),
has a height that is more or less uniform and is inserted into the
groove, which has the same height (10) as the rim, subsequent to
which at least the wall (11) of the groove at its inner
circumference (12) is deformed, decreasing the height of the groove
in that vicinity.
3. Method of inserting the piston-rod scraping ring (7) into the
groove (9) in a dashpot cap (2) recited in claim 1, characterized
in that the rim (8), which is intended to occupy the groove (9),
has a height [that is more or less non uniform] and is inserted
into the groove, which has a height (10) that decreases as it
approaches the center, subsequent to which at least the wall (11)
of the groove at its inner circumference (12) is deformed,
decreasing the height of the groove in that vicinity
4. Method of inserting the piston-rod scraping ring (7) into the
groove (9) in a dashpot cap (2) recited in claim 1, characterized
in that the rim (8), which is intended to occupy the groove (9),
has a height that decreases as it approaches the center and is
inserted into the groove, which has a uniform height (10),
subsequent to which at least the wall (11) of the groove at its
inner circumference (12) is deformed, decreasing the height of the
groove-as it approaches the center and in that the original maximal
height of the rim (8) around the ring (7) approximately equals the
original height of the groove.
Description
[0001] The present invention concerns, first, a piston-rod scraping
ring accommodated in a groove in a dashpot cap as recited in the
preamble to claim 1, and, second, a method of inserting such a ring
in such a groove.
[0002] Piston-rod scraping rings of elastic materials, especially
intended for scraping water and dirt off piston rods, and
accommodated in a groove in a dashpot cap are known from German 3
443 370 C2.
[0003] There are many many ways of securing such piston-rod
scraping rings to the upper cap of a dashpot. One way is disclosed
in German 3 443 370 C2. The cap is secured by means of a groove
that is open radially and, in one direction, axially, by a sleeve
that axially and radially encloses the rim around the ring and is
forced into a bore in the groove. The compression secures the
sleeve and hence the ring. There is a drawback to this approach in
that the sleeve necessitates additional material and work.
[0004] Another approach to attaching such a cap to a dashpot is
known from German Patent 1 140 705. The piston-rod scraping ring is
again inserted in a groove that is open radially and, in one
direction, axially, and secured there radially by compression at
the end of the outer cylinder. One drawback to this approach is
that the ring remains loose and can accordingly get lost before it
is finally secured in place. Furthermore, to protect it from
deformation or eccentricity, the cap must be inserted very
precisely in the groove before the dashpot is assembled.
[0005] German 19 921 696 A1 discloses a seal accommodated in an
inward-opening groove in a cap. The actual sealing mass employed in
such seals must be well inserted axially in the groove.
Furthermore, the mass must be secured in the nut somehow or
radially tensioned, making the groove difficult to machine
precisely and necessitating an additional component.
[0006] The object of the present invention is accordingly a
piston-rod scraping ring and a groove in a dashpot cap improved to
the extent that the ring can easily be inserted into the groove and
secured there until the overall dashpot is assembled.
[0007] This object is attained in accordance with the present
invention as recited in the body of claim 1. Claims 2 through 4
address methods of inserting a piston-rod scraping ring in a groove
in a dashpot cap.
[0008] The advantages of the present invention are that the ring
can be fastened to the cap by simple means and with low expenditure
and-before the dashpot is finally assembled. Embodiments of the
present invention will now be specified with reference to the
accompanying drawing, wherein
[0009] FIG. 1 is a transverse section through the dashpot cap and
its associated components,
[0010] FIG. 2 is a larger-scale depiction, representing the
situation before the ring has been secured, of the groove that
accommodates the ring,
[0011] FIG. 3 is an illustration similar to FIG. 2 representing the
situation after the ring has been inserted,
[0012] FIG. 4 depicts an alternative embodiment in the situation
illustrated in FIG. 2, and
[0013] FIG. 5 depicts the same embodiment in the situation
illustrated in FIG. 3.
[0014] Piston rods usually extend out of dashpots through caps that
close off the dashpots' open ends. FIG. 1 shows such a piston rod 1
and dashpot cap 2. At its outer circumference 2, the cap is sealed
off against an unillustrated outer dashpot cylinder by an O ring 3.
Such caps can be fastened to the cylinders in various ways.
[0015] Cap 2 is provided with various components that center and
seal rod 1 as it travels into and out of the cylinder. These
components are positioned in the vicinity of a bore that extends
through cap 2. Positioned at the bottom of cap 2 is a low-friction
bushing 4 that centers rod 1. Above bushing 4, a gasket 5 is
accommodated in an inward-opening groove and provided with the
requisite radial tension by a compression ring 6.
[0016] At the top of cap 2 is a ring 7 that scrapes water and dirt
off the section of piston rod 1 outside the cylinder as the rod
enters it.
[0017] The rim 8 around piston-rod scraping ring 7 is accommodated
in an inward opening groove 9 in dashpot cap 2. Prior to assembly
of the dashpot, rim 8 is more or less uniformly high. Furthermore,
as will be evident from FIG. 2, the height 10 of groove 9 is also
more or less uniform.
[0018] The height of the rim 8 around piston-rod scraping ring 7,
which is not illustrated in FIG. 2, approximately equals the height
10 of groove 9. Once piston-rod scraping ring 7 has been positioned
with its rim 8 in groove 9, the groove's outer wall 11 is forced
against its inner circumference 12 by a separate tool, a press for
instance, compressing height 10 in the vicinity of the inner
circumference.
[0019] A similar deformation is induced in the embodiment
illustrated in FIGS. 4 and 5.
[0020] When the conditions wherein piston-rod scraping ring 7 will
be employed prescribe that it be forced even more firmly into
groove 9, both the groove and the rim 8 around the ring can in
their original shape be higher toward the center. When outer wall
11 is deformed such that the height 10 of groove 9 decreases as it
approaches inner circumference 12, the rim 8 around the ring will
accordingly be more powerfully compressed.
[0021] It is also possible for the height of the rim 8 around
piston-rod scraping ring 7 to increase outwards, in which event its
maximal height will approximately equal the height 10 of groove 9.
The seating of piston-rod scraping ring 7 will then be secured,
once outer wall 11 has been deformed, by the interlocking
structures and by additional axial compression.
* * * * *