Gas separation – Flexible or collapsible bag type – With securing or supporting means
Reexamination Certificate
1999-02-05
2001-03-06
Simmons, David A. (Department: 1724)
Gas separation
Flexible or collapsible bag type
With securing or supporting means
C055S498000, C055S510000, C074S018200
Reexamination Certificate
active
06197078
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a sleeve filter and more particularly, the present invention relates to a reusable collapsible filter.
BACKGROUND OF THE INVENTION
Generally, arrangements for protecting shafts from exposure to debris or damage have been previously discussed in the art. Representative of such prior proposals is U.S. Pat. No. 4,568,313, issued Feb. 4, 1986, to Diffenderfer et al. The reference details a bellow type cover suited for articulated shafting. The device is a simple dust cover for use in limited environments.
Chaczyk, in U.S. Pat. No. 4,988,113, issued Jan. 29, 1991, provides a sealed protective boot. The boot surrounds a reciprocating shaft for preventing debris from contacting the shaft. Although a useful system, the boot is prone to premature wear, since the boot must absorb the continuous compression and expansion forces. The wear created from this problem is accelerated upon the accretion of debris, fluids etc. on the boot.
In U.S. Pat. No. 5,407,570, issued to Hobson, Jr., Apr. 18, 1995, a flexible filter element is disclosed. The device includes a spring extended between the ends of the arrangement, with one end sealed by a screw. The concept of the invention is to facilitate reuse of the filter as damage occurs in the form of tears, holes etc., in the filter material. As this occurs, the filter is simply shortened by removing the damaged area and screwing the end back onto the arrangement. As is evident, the spring is thus progressively compressed and thus inherently increases the tension of the filter material and thus the proclivity for expedited wear.
Other prior art marginally relevant to the invention includes U.S. Pat. Nos. 4,439,219 and 4,702,483.
In view of the advances made in the prior art, there exists a need for a sleeve or in-line type filter capable of long term heavy duty. The present invention addresses this need.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an improved filter arrangement designed for long term usage and which is reusable upon soiling.
A further object of the present invention is to provide a filter element, comprising:
opposed rigid ends in spaced relation along a longitudinal axis, each end of the ends having an aperture adapted for receiving a shaft in collocation therethrough, apertures of the ends being in registration;
retaining means on each end of the opposed ends;
biasing means extending between and retained by the retaining means in the opposed ends, the biasing means positioned between the opposed ends to provide an unobstructed path between the apertures; and
flexible filter means positioned about the biasing means and the opposed ends defining an internal volume, the filter means for reducing debris ingress into the internal volume.
The use of a spring, as an example, for the biasing means is particularly useful when positioned within the filter element with the filter material positioned about the spring. This facilitates simple removal of the material from the structure for washing and subsequent reuse. The present invention is suitable for use in positioning about fluid operated shafts and in particular, drilling shafts. Once in position, the arrangement functions when compressed or expanded, to prevent metal particulates, fluids or other debris from entering into the shaft housing or contacting the shaft. Considering that the spring is retained by the opposed ends, substantially all of the axial force during compression and expansion is realized by the ends, with the filter material remaining untensioned. As a concomitant advantage, the spring maintains the filter material in spaced relation to a shaft about which the filter is placed. This avoids contact between the two elements and imports “body” to the filter material.
Depending upon the intended use of the device, the filter material may be selected from a host of different fabrics including both synthetic and nonsynthetic. In the case of woven materials, cotton, wool, nylon, burlap, etc. may be employed and for non-woven materials, felt, sponge, treated paper inter alia. In summary, any suitable porous material may be employed. As an adjunct feature, moisture, heat and flame retardants may be added to the filter.
According to a further object of the present invention, there is provided a fluid operated reciprocating piston in combination with a filter, comprising:
a piston assembly including a piston shaft and piston housing within which the piston shaft is mounted for reciprocal motion relative to the housing, the piston having an end, the housing having an end wall;
a filter element positioned about the piston shaft, the filter element including opposed rigid ends in spaced relation along a longitudinal axis, each end of the ends having an aperture for receiving the shaft in collocation therethrough, apertures of the ends being in registration;
retaining means on each end of the opposed ends; and
biasing means extending between and retained by the retaining means in the opposed ends, the biasing means positioned between the opposed ends to provide an unobstructed path between the apertures, the biasing means for permitting compression and expansion of the filter element during reciprocal movement of the piston shaft; and
flexible filter means surrounding the biasing means releasably connected to the opposed ends defining an internal volume, the filter means for reducing debris ingress into the piston housing and onto the piston shaft.
The spring bias is retained and located by the opposed ends and more particularly by recesses within the inside wall of each end. This allows some tolerance for the spring to move in the event that any irregular forces are experienced by the shaft in use and thus prevents premature wear of the recesses. The exterior of the ends also secure the filter material. The securement may be permanent or may provide any number of variations of fasteners for cooperation with mating fasteners on a removable filter sheet wrapped about the ends and spring. As examples, glue, hook and loop, tape, snaps, buttons, chemical bonding, inter alia may be employed.
Having thus described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments.
REFERENCES:
patent: 515769 (1894-03-01), Harris
patent: 3598192 (1971-08-01), Becker
patent: 3722186 (1973-03-01), Parker et al.
patent: 3927576 (1975-12-01), Colletti
patent: 4002079 (1977-01-01), Hall
patent: 4439219 (1984-03-01), Lambrecht
patent: 4568313 (1986-02-01), Diffenderfer et al.
patent: 4702483 (1987-10-01), Ukai et al.
patent: 4988113 (1991-01-01), Chaczyk
patent: 5407570 (1995-04-01), Hobson, Jr.
patent: 5528975 (1996-06-01), Gautier et al.
patent: 5605748 (1997-02-01), Kennedy et al.
(Marks & Clerk)
Adams Glen
Lawrence Frank M.
Sharpe Paul S.
Simmons David A.
LandOfFree
Sleeve filter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sleeve filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sleeve filter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2502591