U.S. patent application number 09/751003 was filed with the patent office on 2001-07-05 for dashpot with two cylinders.
Invention is credited to Hartig, Ulrich, Poth, Oliver, Rehse, Jorg, Sasse, Thomas.
Application Number | 20010006135 09/751003 |
Document ID | / |
Family ID | 7626775 |
Filed Date | 2001-07-05 |
United States Patent
Application |
20010006135 |
Kind Code |
A1 |
Sasse, Thomas ; et
al. |
July 5, 2001 |
Dashpot with two cylinders
Abstract
A dashpot with an inner cylinder (3) accommodated in an outer
cylinder (1), and a piston (6) traveling back and forth inside on
the end of a piston rod (5) and separating the inner cylinder into
two chambers (7 & 8). The piston rod enters the cylinders
through a hole at one end that seals it off and positions it. The
outer cylinder is provided with a base (4) at the end opposite the
end with the hole. The inner cylinder is centered along the axis of
the outer cylinder at each end. The cylindrical gap (2) between the
two cylinders is provided with a fluid-accommodating compartment
(11) and, toward the base, a port (13) opening into the adjacent
chamber (8). The chamber accommodates, preferably above the port, a
vent (12). The mutually contacting ends of the cylinders are hot or
cold welded together at the base end or at the end remote from the
base.
Inventors: |
Sasse, Thomas; (Ennepetal,
DE) ; Rehse, Jorg; (Gevelsberg, DE) ; Hartig,
Ulrich; (Hermeskeil, DE) ; Poth, Oliver;
(Holzerath, DE) |
Correspondence
Address: |
Dr. Max Fogiel
61 Ethel Road West
Piscataway
NJ
08854
US
|
Family ID: |
7626775 |
Appl. No.: |
09/751003 |
Filed: |
December 28, 2000 |
Current U.S.
Class: |
188/300 ;
188/315; 188/322.19 |
Current CPC
Class: |
F16F 9/3235
20130101 |
Class at
Publication: |
188/300 ;
188/315; 188/322.19 |
International
Class: |
F16F 009/32; F16F
009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 5, 2000 |
DE |
100 00 179.3-12 |
Claims
1. Dashpot with an inner cylinder (3) accommodated in an outer
cylinder (1), and a piston (6) traveling back and forth inside on
the end of a piston rod (5) and separating the inner cylinder into
two chambers (7 & 8), whereby the piston rod enters the
cylinders through a hole at one end that seals it off and positions
it, the outer cylinder is provided with a base (4) at the end
opposite the end with the hole, the inner cylinder is centered
along the axis of the outer cylinder at each end, and the
cylindrical gap (2) between the two cylinders is provided with a
fluid-accommodating compartment (11) and, toward the base, a port
(13) opening into the adjacent chamber (8), which accommodates,
preferably above the port, a vent (12), characterized in that the
mutually contacting ends of the cylinders are hot or cold welded
together at the base end or at the end remote from the base.
2. Dashpot as in claim 1, characterized in that the ends of the
cylinders (1 & 3) are welded to a separate base (4).
3. Dashpot as in claim 1, characterized in that the ends of the
cylinders (1 & 3) are molded hot or cold into a base (4).
4. Dashpot as in one or more of claims 1 through 3, characterized
in that the base (4) is provided with a short upward-and-inward
tapering section (17) of approximately the same diameter as the
inner cylinder (3) that includes a vent (12) and that the inner
cylinder continues beyond.
5. Dashpot as in one or more of claims 1 through 4, characterized
in that the inner cylinder (3) has inward-extending depressions
(21) above the ports (13 or 19) between the cylindrical gap (2) and
the chamber (8) to accommodate the vent (12).
Description
LIST OF PARTS
[0001] 1. outer cylinder
[0002] 2. cylindrical gap
[0003] 3. inner cylinder
[0004] 4. base
[0005] 5. piston rod
[0006] 6. piston
[0007] 7. chamber
[0008] 8. chamber
[0009] 9. open end
[0010] 10. packing
[0011] 11. compartment
[0012] 12. vent
[0013] 13. port
[0014] 14. ports
[0015] 15. depression
[0016] 16. screw
[0017] 17. inward-tapering section
[0018] 18. collar
[0019] 19. port
[0020] 20. lower end
[0021] 21. depression
[0022] The present invention concerns a dashpot with two
cylinders.
[0023] Two-cylinder dashpots of this genus are preferred for
eliminating the vibrations that occur between a vehicle and its
wheels. Such absorbers generally comprise two loosely concentric
cylinders, the gap between them occupied by a cushion of gas that
compresses to accommodate the gas forced in by a piston rod that
slides in and out to various extents.
[0024] The base of the outer cylinder in a dashpot disclosed in
German OS 1 750 679 is molded on. That of the outer cylinder
disclosed in WO 97/16656 on the other hand is separate and welded,
cemented, or soldered on.
[0025] Both embodiments have the drawback that precisely centering
the inner cylinder in relation to the outer cylinder requires
considerable care.
[0026] The object of the present invention is accordingly a simple
and reliable means of attaching the outer cylinder to the inner
cylinder of such a dashpot.
[0027] This object is attained in accordance with the present
invention in a dashpot of the aforesaid genus by the
characteristics recited in the body of claim 1. Advantageous
additional and advanced embodiments are addressed by claims 2
through 5.
[0028] The major advantage of the present invention is that the
outer cylinder is reliably secured to the inner cylinder.
Furthermore, however, the means of attachment are simple, which
considerably decreases the cost of manufacture.
[0029] One embodiment of the present invention will now be
specified with respect to the accompanying drawing, wherein
[0030] FIG. 1 is a section through a dashpot with two
cylinders,
[0031] FIG. 2 illustrates another version of the dashpot,
[0032] FIG. 3 is a larger-scale illustration of the base of a
dashpot, and
[0033] FIG. 4 illustrates another version of the base illustrated
in FIG. 3.
[0034] A dashpot comprises an inner cylinder 3 centered inside an
outer cylinder 1 with a cylindrical gap 2 left between them. Outer
cylinder 1 is provided with a base 4. A piston rod 5 travels into
and out of the end of the dashpot opposite base 4 through a hole at
the center sealed gas-tight by packing 10. Mounted on the lower end
of piston rod 5 and accordingly traveling back and forth inside
inner cylinder 3 is a piston 6, the spaces at each face
constituting pressure chambers 7 and 8. A compressible-gas
accommodating compartment 11 compensates for variations in the
volume of gas forced in by piston rod 5 as it travels in and out.
There is a vent 12 at the base 4 of inner cylinder 3. Below vent 12
is a port 13 that opens into cylindrical gap 2. Above packing 10
are other ports 14, which open into gas-accommodating compartment
11 and allow the removal of excess lubricant from piston rod 5.
[0035] The open ends 9 of the outer cylinder 1 and inner cylinder 3
in the embodiment illustrated in FIG. 1 are welded together and
folded in, leaving a round hole at the center to align piston rod 5
above packing 10. Vent 12 is fastened to base 4 at the bottom of
outer cylinder 1 by interlocking beads and grooves. The edge of
base 4 is welded to the edge of outer cylinder 1. A depression 15
accommodates the head of a screw 16 employed to adjust vent 12.
[0036] FIG. 2 illustrates a variant of the embodiment illustrated
in FIG. 1. The base 4 in this version is also welded to outer
cylinder 1, but merges into an inward-tapering section 17 with vent
12 mounted on its upper edge and provided with a collar 18. The
section of inner cylinder 3 extending above the transition between
base 4 and inward-tapering section 17 is provided with ports 19.
There is a similar depression 15 in base 4 to accommodate the head
of a vent-adjustment screw 16.
[0037] The upper end of the two-cylinder dashpot, which provides
access to the piston rod, in the embodiment illustrated in FIG. 3
is conventional, and only the lower end is accordingly illustrated.
The bottom edge of outer cylinder 1 rests against the edge of
inward-tapering section 17 of inner cylinder 3, and both edges have
been molded cold or hot around base 4 with no machining involved.
Vent 12, which is fastened as in the embodiment illustrated in FIG.
2, can be introduced along with any other components through the
upper, open, end of the dashpot. Once the dashpot has been,
conventionally, closed and the cushioning and
pressure-accommodating gases injected, the dashpot is finished.
Here again, as in the embodiments illustrated in FIGS. 1 and 2,
base 4 is provided with a depression 15.
[0038] The base 4 of the embodiment illustrated in FIG. 4 is
similar to the base 4 specified with reference to FIG. 3, although
inner cylinder 3 is in this case in a single part, and vent 12 must
accordingly be inserted through it from above. To facilitate
assembly, the lower end 20 of inner cylinder 3 tapers in slightly,
preventing damage to the cylinder's inner surface from the entering
vent. Ports 19 are here as well provided at the transition to lower
end 20. A depression 21 demarcating the bottom edge of vent 12 is
punched out along with ports 19.
* * * * *