GB2053413A - Piston assembly - Google Patents
Piston assembly Download PDFInfo
- Publication number
- GB2053413A GB2053413A GB8021184A GB8021184A GB2053413A GB 2053413 A GB2053413 A GB 2053413A GB 8021184 A GB8021184 A GB 8021184A GB 8021184 A GB8021184 A GB 8021184A GB 2053413 A GB2053413 A GB 2053413A
- Authority
- GB
- United Kingdom
- Prior art keywords
- piston
- annular
- retaining
- piston body
- plastics material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000463 material Substances 0.000 claims abstract description 14
- 239000000872 buffer Substances 0.000 claims abstract description 13
- 229920003023 plastic Polymers 0.000 claims abstract description 13
- 239000004033 plastic Substances 0.000 claims abstract description 13
- 238000007789 sealing Methods 0.000 claims abstract description 7
- 229920000459 Nitrile rubber Polymers 0.000 claims description 4
- 229920002635 polyurethane Polymers 0.000 claims description 4
- 239000004814 polyurethane Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J1/00—Pistons; Trunk pistons; Plungers
- F16J1/10—Connection to driving members
- F16J1/12—Connection to driving members with piston-rods, e.g. rigid connections
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
- Actuator (AREA)
- Fluid-Damping Devices (AREA)
Abstract
A piston of a piston and cylinder device comprises a piston rod 1, a body 7 made of plastics material attached to the rod 1 and a seal arranged on the body and having two annular lips 9 in the form of truncated cones facing in opposite directions and resiliently pre-stressed outwards, the body 7 having a cylindrical portion the ends 14, 15 of which project beyond the lips 9 to form buffer surfaces to stop the piston at the end of its stroke. The piston body may be in two parts which are clamped about a third part which carries the sealing lips. <IMAGE>
Description
SPECIFICATION
Piston assembly
The invention relates to a piston assembly for a pneumatic or hydraulic working cylinder, comprising a piston rod, a piston body made of a plastics material, which is attached to a retaining area of the piston rod and fulfils a supporting and sealing function, and a piston seal arranged on the piston body and provided with two annular lips extending in opposite directions.
With known pistons of this type, the components listed above are either separated from each other, thus having to be assembled individually, which requires special holding equipment and assembly processes, or else the piston body and the piston rod form a rigid onepiece assembly. In either case, the manufacture and assembly of the piston are more expensive than its applications would justify. Other known assemblies, too, involve relatively complex assembly methods, frequently necessitating fairly expensive additional measures to prevent knocking and jolts in the end positions of the piston.
It is therefore an object of the present invention to obviate or mitigate these disadvantages.
According to the present invention there is provided a piston assembly for a pneumatic or hydraulic working cylinder, comprising a piston rod, a piston body made of a plastics material, which is attached to a retaining area of the piston rod and fulfils a supporting and sealing function, and a piston seal arranged on the piston body and provided with two annular lips extending in opposite directions, the annular lips essentially having the shape of a truncated cone and being resiliently prestressed to widen outwards, and the piston body having a substantially cylindrical trunk the end faces of which project beyond the ends of the annular lips in the axial direction and form buffer surfaces to stop the piston at the end of its stroke, an annular space being maintained between the trunk and each annular ring.
An advantageous assembly might for instance comprise a piston body having an essentially cylindrical trunk, the faces of which project beyond the ends of the annular lips in the axial direction and form buffer surfaces to stop the piston at the end of stroke, or a piston body comprising two supporting rings made of a plastics material and serving as buffers, provision being made for a predetermined play between them and an annular space being maintained between the trunk and each annular lip.
The piston body according to the invention, which is made of a plastics material, is simply constructed and cost effective in manufacture while serving several functions. In the first instance, it serves as a supporting element, similar to the known rigid piston body; at the same time, however, it serves as a piston seal and as buffers matched to the distance of piston travel in either direction, thus providing effective buffering without additional provisions. Assembly, too, is
very simple.
Embodiments of the present invention are
described below by way of example only with
reference to the accompanying drawing, in which:
Fig. 1 is a section through a first embodiment of
a piston according to the invention;
Fig. 2 is a section through a second
embodiment of a piston according to the
invention.
The embodiment of a piston for hydraulic and -pneumatic applications which is shown in Fig. 1 is
mainly recommended for smaller dimensions. The
end of the piston rod 1, to which the piston body is
to be attached, is provided with a retaining area 2.
-This comprises an essentially cylindrical section 3
of reduced diameter, followed by a conical section
4 tapering outwards, a further cylindrical section 5
of yet further reduced diameter and an external
retaining head 6, the diameter of which is
approximately equal to the diameter of the first
cylindrical section 3.
The piston body 7, which is moulded in one
piece from a material such as polyurethane or
buna N, has a bore 8 complementary to the
retaining area 2. The piston rod 1 is inserted into
the bore 8 of the piston body 7 under slight
pressure and is there locked in place. In this way,
the piston body 7 is attached to the piston rod 1,
while a sealing effect is ensured between the bore
8 and the retaining area 2 of the piston rod 1.
The piston body 7 combines the supporting
functions of known rigid piston bodies with the
sealing function of known piston seals. For this
purpose, it is provided with two annular lips 9, 10
of truncated cone shape extending and widening
towards the end faces of the piston body 7.
Annular spaces 11, 12 provided between the lips
9, 10 and the essentially cylindrical trunk 1 3 of
the piston body 7 maintain the elasticity of the
lips 9, 10. The end faces 14, 1 5 of the trunk 13 of the piston body 7 project beyond the ends of the
annular lips 9, 10 in the axial direction. They serve
as elastic buffers to stop the piston at the end of
its stroke.
The embodiment of the piston illustrated in Fig.
2 is primarily suitable for larger dimensions, which would pose tooling problems in attempting to produce a one-piece piston body 7. Any components of the embodiment shown in Fig. 2 which correspond to those of Fig. 1 are identified
by the same reference number plus 100.
The piston rod 101 is once again provided with a retaining area 102, in this case consisting of a
uniform cylindrical section 103 of reduced diameter and an external retaining head 1 06. The diameter of the retaining head 106 approximately
corresponds to the diamter of the piston rod 1
outside the retaining area 102.
The piston body 107, which is entirely made of a plastics material and attached to the retaining area 102 of the piston rod 101, here comprises three separate components which are detachably assembled.
The two truncated cone shaped annular lips 109, 110, which widen towards the end faces of the piston body 107, represent, together with a retaining rib 120 extending radially inwards, a first part. The retaining rib 120, whose inner circumference is at a distance from the retaining area 102 of the piston rod 101, is provided with an annular dovetailed extension 121. This part should preferably be made of buna N.
The other components of the piston body 107 are two supporting rings 1 13a, 1 13b, which essentially fulfil the function of the trunk 1 3 of the embodiment illustrated in Fig. 1. Each of the supporting rings 113a. 113b, which are preferably made of polyurethane, is provided with a recess 122a, 122b at the end facing the other supporting ring, each recess 122a, 122b complementing the shape of half of the retaining rib 120 and half of the associated dovetailed extension 1 21. Between the supporting rings 113a, 1 13b and the annular lips 109,110, two annular spaces 111, are maintained to ensure the elasticity of the lips 109, 110.The external end faces 114, 115 of the supporting rings 1 13a, 1 13b once again project beyond the outer ends of the annular lips 109, 110 in the axial direction, representing elastic buffers to stop the piston at the end of its stroke.
In this embodiment, too, the piston body has an essentially cylindrical trunk, the end faces of which project beyond the ends of the annular lips in the axial direction and form buffers to stop the piston at the end of its stroke, the buffer surfaces in this case being provided by two supporting rings 1 13a, 1 13b made of plastics material, provision being made for a predetermined play in between, which is, however, not illustrated in the drawing.
As can be seen in the drawing, the two supporting rings 1 13a, 1 13b are, partly as a result of the play provided between them, axially compressed during fitting to the piston rod 101, thus firmly gripping the retaining rib 120. The extension 121 of the retaining rib 120 radially secures the annular lips 109, 110.
Both embodiments of the piston described above are cost effective in manufacture and assembly.
Claims (11)
1. A piston assembly for a pneumatic or
hydraulic working cylinder, comprising a piston
rod, a piston body made of a plastics material,
which is attached to a retaining area of the piston
rod and fulfils a supporting and sealing function,
and a piston seal arranged on the piston body and
provided with two annular lips extending in
opposite directions, the annular lips essentially
having the shape of a truncated cone and being
resiliently prestressed to widen outwards, and the
piston body having a substantially cylindrical trunk
the end faces of which project beyond the ends of
the annular lips in the axial direction and form
buffer surfaces to stop the piston at the end of its
stroke, an annular space being maintained
between the trunk and each annular ring.
2. A piston for a pneumatic or hydraulic working cylinder, comprising a piston rod, a piston body made of a plastics material fitted to the piston rod and a piston seal arranged on the piston body and provided with two annular lips extending in opposite directions, which, in accordance with claim 1, have substantially the shape of a truncated cone and are resiliently prestressed to widen outwards, the piston body having an essentially cylindrical trunk, the end faces of which project beyond the ends of the annular lips in the axial direction and form buffer surfaces to stop the piston at the end of its stroke, the piston body being provided with two supporting rings made of a plastics material and serving a buffer surfaces, provision being made for a predetermined play between them and an annular space being maintained between the trunk and each annular lip.
3. A piston according to claim 1 or 2, wherein the piston body together with the sealing lips forms a one-piece unit made of a plastics material such as polyurethane or buna N.
4. A piston according to any of claims 1 to 3, wherein the piston body consists of three parts: two of these being the supporting rings with the buffer surfaces made of a plastics material, the third part, which is clamped between the supporting rings and is also made of a plastics material, comprising the annular lips and a radial retaining rib, the supporting rings having recesses complementing the shape of the retaining ribs at their adjacent ends.
5. A piston according to claim 4, wherein the retaining rib has a dovetailed extension at its internal circumference.
6. A piston according to claim 4 or 5, wherein the supporting rings are made of polyurethane.
7. A piston according to any of claims 4 to 6, wherein the part comprising the annular lips and the retaining rib is made of buna N.
8. A piston according to any of claims 1 to 7, wherein the retaining area of the piston rod comprises a cylindrical section of reduced diameter and an external retaining head, whose diameter corresponds to the diameter of the piston rod remote from the retaining area.
9. A piston according to any of claims 1 to 8, wherein the retaining area of the piston rod comprises from inside outwards: a first cylindrical section of reduced diameter, a section tapering outwards, a second cylindrical section of still further reduced diameter and an external retaining head, whose diameter corresponds to the diameter of the first cylindrical section.
10. A piston assembly for a pneumatic or hydraulic working cylinder, substantially as hereinbefore described with reference to Fig. 1 or
Fig. 2 of the accompanying drawings.
11. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2927777A DE2927777C3 (en) | 1979-07-10 | 1979-07-10 | Piston arrangement for a pneumatic or hydraulic working cylinder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2053413A true GB2053413A (en) | 1981-02-04 |
| GB2053413B GB2053413B (en) | 1983-01-19 |
Family
ID=6075317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8021184A Expired GB2053413B (en) | 1979-07-10 | 1980-06-27 | Piston assembly |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5620862A (en) |
| BR (1) | BR8004271A (en) |
| DE (1) | DE2927777C3 (en) |
| FR (1) | FR2465931B1 (en) |
| GB (1) | GB2053413B (en) |
| IT (1) | IT1131930B (en) |
| NL (1) | NL187410C (en) |
| SE (1) | SE443034B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998053221A1 (en) * | 1997-05-21 | 1998-11-26 | Cabex Ag | Device for adjusting the length of a support and method for producing same |
| WO2001040685A1 (en) * | 1999-11-30 | 2001-06-07 | Parker-Hannifin Corporation | Snap-in retainer for a fluid seal |
| US8557197B2 (en) | 2008-11-05 | 2013-10-15 | Hamilton Bonaduz Ag | Radial sliding seal component for metering devices and metering device having such a radial sliding seal component |
| US10654451B2 (en) | 2015-05-20 | 2020-05-19 | Denso Corporation | System for cleaning on-vehicle optical sensor and method for the same |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2919472B2 (en) * | 1988-02-19 | 1999-07-12 | 三洋電機株式会社 | Program timer device |
| JPH01141961U (en) * | 1988-03-23 | 1989-09-28 | ||
| DE4110542A1 (en) * | 1991-03-30 | 1992-10-22 | Grau Gmbh | Piston for vehicle air brake - has piston components moulded in plastic along seal recess, and having press connection to body |
| JP2890217B2 (en) * | 1991-08-02 | 1999-05-10 | 本田技研工業株式会社 | Valve train for internal combustion engine |
| JP3248081B2 (en) * | 1992-01-28 | 2002-01-21 | 日立精機株式会社 | Automatic program creation device with automatic cutting axis change function |
| JPH0564505U (en) * | 1992-02-06 | 1993-08-27 | 株式会社オティックス | accumulator |
| DE4421968C2 (en) * | 1994-06-23 | 1997-09-11 | Bilstein August Gmbh Co Kg | Damping piston seal |
| DE19520670A1 (en) * | 1995-02-02 | 1996-08-08 | Teves Gmbh Alfred | Automatic braking system piston design in vehicle |
| JP2001116146A (en) | 1999-10-18 | 2001-04-27 | Smc Corp | Structure for mounting piston packing |
| JP2004224439A (en) * | 2003-01-24 | 2004-08-12 | Daiwa Can Co Ltd | Outer piston of metering device |
| JP4169192B2 (en) * | 2003-02-10 | 2008-10-22 | 大和製罐株式会社 | Piston seal member |
| WO2012011150A1 (en) * | 2010-07-21 | 2012-01-26 | 三浦工業株式会社 | Piston structure and control valve |
| DE102011007643A1 (en) * | 2011-04-19 | 2012-10-25 | Gustav Magenwirth Gmbh & Co. Kg | Encoder for hydraulic actuator of disk brake of bicycle, has clamping unit that is formed at internal cross-section of handlebar by inner wedging |
| JP5646004B2 (en) * | 2013-05-27 | 2014-12-24 | ハミルトン・ボナドゥーツ・アーゲー | Radial sliding seal element for a weighing device and a weighing device having such a radial sliding seal element |
| JP6597334B2 (en) * | 2015-05-28 | 2019-10-30 | 株式会社デンソー | In-vehicle optical sensor cleaning device |
| DE102016002947B4 (en) * | 2016-03-11 | 2022-11-24 | Hakki Aygün | expansion device |
| JP7033598B2 (en) * | 2017-07-31 | 2022-03-10 | 株式会社日立産機システム | Reciprocating compressor |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE7607218U1 (en) * | 1979-05-23 | Festo-Maschinenfabrik Gottlieb Stoll, 7300 Esslingen | Pistons, especially for a pneumatic cylinder | |
| DE842308C (en) * | 1950-09-14 | 1952-06-26 | Continental Gummi Werke Ag | Piston ring for pumps |
| DE1719235U (en) * | 1955-07-26 | 1956-03-22 | Bbc Brown Boveri & Cie | PISTONS FOR HYDRAULIC AND PNEUMATIC CONTROLS OD. DGL. |
| DE1729909U (en) * | 1956-06-30 | 1956-09-13 | Boris V Schlippe | LIP SEAL PISTON. |
| DE1748885U (en) * | 1957-03-16 | 1957-07-18 | Walter Breiter K G | PISTONS FOR SUCTION AND PRESSURE PUMPS. |
| US3155014A (en) * | 1961-01-23 | 1964-11-03 | Garlock Inc | Plastic piston |
| US3176595A (en) * | 1963-05-22 | 1965-04-06 | Galland Henning Mfg Company | Plastic piston assembly |
| DE2631382C3 (en) * | 1976-07-13 | 1982-02-18 | Festo-Maschinenfabrik Gottlieb Stoll, 7300 Esslingen | Pistons, especially for a pneumatic cylinder |
-
1979
- 1979-07-10 DE DE2927777A patent/DE2927777C3/en not_active Expired
-
1980
- 1980-06-27 GB GB8021184A patent/GB2053413B/en not_active Expired
- 1980-07-08 IT IT23329/80A patent/IT1131930B/en active
- 1980-07-09 BR BR8004271A patent/BR8004271A/en not_active IP Right Cessation
- 1980-07-09 SE SE8005030A patent/SE443034B/en not_active IP Right Cessation
- 1980-07-10 JP JP9332980A patent/JPS5620862A/en active Pending
- 1980-07-10 NL NLAANVRAGE8003984,A patent/NL187410C/en not_active IP Right Cessation
- 1980-07-11 FR FR8015434A patent/FR2465931B1/en not_active Expired
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998053221A1 (en) * | 1997-05-21 | 1998-11-26 | Cabex Ag | Device for adjusting the length of a support and method for producing same |
| US6471178B1 (en) | 1997-05-21 | 2002-10-29 | Cabex Ag | Device for adjusting the length of a support and method for producing same |
| WO2001040685A1 (en) * | 1999-11-30 | 2001-06-07 | Parker-Hannifin Corporation | Snap-in retainer for a fluid seal |
| US6422569B1 (en) | 1999-11-30 | 2002-07-23 | Parker-Hannifin Corporation | Snap-in retainer for a fluid seal |
| US8557197B2 (en) | 2008-11-05 | 2013-10-15 | Hamilton Bonaduz Ag | Radial sliding seal component for metering devices and metering device having such a radial sliding seal component |
| US9180457B2 (en) | 2008-11-05 | 2015-11-10 | Hamilton Bonaduz Ag | Radial sliding seal with subassembly for metering devices, and metering device with such a radial sliding seal subassembly |
| US9186675B2 (en) | 2008-11-05 | 2015-11-17 | Hamilton Bonaduz Ag | Radial sliding seal subassembly for metering devices, and metering device with such a radial sliding seal subassembly |
| US10654451B2 (en) | 2015-05-20 | 2020-05-19 | Denso Corporation | System for cleaning on-vehicle optical sensor and method for the same |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8005030L (en) | 1981-01-11 |
| BR8004271A (en) | 1981-01-27 |
| IT8023329A0 (en) | 1980-07-08 |
| JPS5620862A (en) | 1981-02-26 |
| GB2053413B (en) | 1983-01-19 |
| DE2927777B2 (en) | 1981-06-19 |
| NL187410B (en) | 1991-04-16 |
| IT1131930B (en) | 1986-06-25 |
| DE2927777C3 (en) | 1984-04-19 |
| NL187410C (en) | 1991-09-16 |
| FR2465931B1 (en) | 1985-10-11 |
| SE443034B (en) | 1986-02-10 |
| FR2465931A1 (en) | 1981-03-27 |
| DE2927777A1 (en) | 1981-01-15 |
| NL8003984A (en) | 1981-01-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| GB2053413A (en) | Piston assembly | |
| US3980309A (en) | Two-part scraper-type shaft-seal | |
| EP0479808B1 (en) | Piston sealing and dampening device | |
| US4854428A (en) | Double-acting hydraulic piston-and-cylinder device | |
| CA2042238A1 (en) | Floating seal arrangement | |
| US3071386A (en) | Fluid pressure seals | |
| DK164188B (en) | COMPOUND SEAL | |
| CA2083565A1 (en) | Shaft-wall seal with elastomerically protected reinforcement rings | |
| US4208060A (en) | Sealed shaft | |
| JPH0621664B2 (en) | High-voltage tailor seal seal | |
| GB2033537A (en) | Piston for pneumatic actuator | |
| US3717394A (en) | Sealing device for a bearing mounted on a shaft | |
| US4407517A (en) | Protective boot for solenoid | |
| EP0252636A3 (en) | Self-compensating seal | |
| US4346903A (en) | High-pressure seal in piston | |
| US4253675A (en) | Improvements of sealed shafts | |
| US4004499A (en) | Bolt-on piston assembly | |
| CA2102472A1 (en) | Seal Arrangement | |
| US3178191A (en) | Sealing structure | |
| US3354794A (en) | Piston structure | |
| GB2045389A (en) | Piston-cylinder assemblies | |
| GB2073845A (en) | Improvements in and Relating to Piston Seals | |
| GB2044395A (en) | Attaching Diaphragm of Rolling Lobe Airspring | |
| US6796216B2 (en) | Guide for the piston rod of a piston-cylinder assembly | |
| US3556539A (en) | Sealing means for ball or roller bearings |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20000626 |