Expansible chamber devices – With cushioning means effective over a portion only of stroke
Patent
1991-11-01
1993-03-16
Denion, Thomas E.
Expansible chamber devices
With cushioning means effective over a portion only of stroke
92107, 92240, 92245, 91 27, 91 31, 91409, F01B 1107
Patent
active
051934337
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a piston sealing and dampening device of the kind disclosed in the preamble to claim 1.
Such a device is known from EP-B-1-0082829 (relating to a so-called slot cylinder), the inner and outer sealing ring lips each being formed on a separate sealing ring. One sealing ring is inserted in a circumferential groove on the outer cylindrical surface of the piston, while the other sealing ring is placed in an external groove on the sleeve portion projecting into the cylinder chamber. By this arrangement the separate sealing rings can indeed fulfil their respective functions, i.e. piston sealing and end position dampening, but most fabrication and assembly will be relatively complicated and costly.
The object to the present invention is to provide, against this background, an integrated device, which in a simple way functions both as end position dampening and piston sealing means. This object is achieved by a device having the characterizing features stated in claim 1.
The following advantages are thus obtained:
an integrated sealing ring serves both as end position dampening and piston sealing means;
the implementation is simple and cheap, and assembly can be carried out rapidly in series production;
by the intermediate web portion of the sealing ring, covering the end surface of the piston, the ring can also serve as an impact dampening and sound silencing means when the piston strikes against the cylinder end cap.
Further advantageous distinguishing features are disclosed in the sub-claims and will be apparent from the detailed description below, referance being made to the accompanying drawings, where
FIG. 1A, 1B and 1C are central, longitudinal sections of an embodiment of the inventive device, for a single-acting pressurized-fluid cylinder, in three different positions of the piston;
FIG. 2 illustrates the device in a slot cylinder (cylinder without piston rod);
FIG. 3 illustrates the device in a double-acting pressurized-fluid cylinder provided with a piston rod; and
FIGS. 4, 4a, FIG. 5 and FIG. 6 illustrate modified embodiments of the device according to the invention, only the end cap and part of the cylinder being shown in central sections.
In FIGS. 1A, 1B and 1C there is schematically illustrated a single-acting pneumatic cylinder with opposite end caps 1a, 1b, a cylinder tube 2 and a piston 3, having its piston rod 4 projecting out through an opening in the end cap 1b. The necessary sealing members between the cylinder tube and end caps, the bushing for the piston rod and the pressurized-air connections have been excluded on the drawings, since these components do not have any essential importance for the invention.
The piston 3 is formed with a central, cylindrical recess 3a facing towards the end cap 1a, such that when the piston approaches the left end position in the figures, the piston accommodates a circular-cylindrical sleeve portion 5 projecting into the cylinder chamber from the end cap 1a. The central bore in this cylindrical portion 5 communicates with the pressurized-air port 6 of the cylinder for supply and discharge of pressurized-air to and from the active cylinder chamber to the left of the piston 3.
In the region of the sleeve portion 5 there is formed an annular space between the outside of the sleeve portion 5 and the inside of the cylinder tube 2 adjacent the end cap 1a. A duct 7 connected to an adjustable constriction 9 and passing through the end cap opens into this annular space 8.
The piston 3 is provided with a sealing ring 10, which in accordance with the invention has the task of sealing against the inside of the cylinder tube 2 to serve as a piston seal, and also against the outside of the sleeve portion 5 to serve as end position dampening means, since in the piston position illustrated in FIG. 1B it encloses air in the space 8 (which can only be discharged via the constriction 9). The sealing ring 10 has a radially outward part provided with a fastening bead 10a, which is accommodated in a circumferential groove 11 on the piston 3. The sealing rin
REFERENCES:
patent: 2935047 (1960-05-01), Ortman et al.
patent: 3267815 (1966-08-01), Ortman et al.
patent: 3296942 (1967-01-01), Nelson
patent: 3835753 (1974-09-01), Bunyard
AB Mecman
Denion Thomas E.
LandOfFree
Piston sealing and dampening device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Piston sealing and dampening device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Piston sealing and dampening device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-345479