Shielding apparatus for linear actuator
US4392390A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 1981 |
| Grant date | Jul 12, 1983 |
| Priority date | — |
| Expiry date | Mar 2, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/18712
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A shielding bladder for the venting arrangement of a linear actuator having a housing, a reciprocable member disposed therein for linear reciprocable movement therethrough, and a venting arrangement in the housing for communicative flow of ambient air into and out of the housing during operation. The bladder is a sleeve sealably affixed exteriorly to the housing enclosing the venting arrangement and defining a chamber between the sleeve and housing that contains a volume of air for contractionally expelling the air into the housing in response to increases in its volumetric capacity resulting upon outward reciprocation of the reciprocating member and expansionally receiving air from the housing in response to decreases in its volumetric capacity upon inward reciprocation of the reciprocating member. Thus, a controlled volume of clean air free of excess moisture is contained in equilibrium between the bladder and the housing to permit normal actuator operation while preventing entrance of debris and excess moisture thereinto through its vent arrangement. A cylindrical cover protects the bladder from degradation by the ambient atmosphere and environment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.