Air filter restriction indicating device

• US 4,445,456 A
• Filed: 06/16/1981
• Issued: 05/01/1984
• Est. Priority Date: 06/19/1978
• Status: Expired due to Term

• Current Assignee: Epci Acquisition Corp.
• Original Assignee: Engineered Products Company (Donaldson Company Incorporated)
• Inventors: Nelson, Joseph N.
• Primary Examiner(s): Yasich, Daniel M.
• Application Number:
  US06/273,699
• Time in Patent Office: 1,050 Days
• Field of Search: 116/272, 116/268, 116/274, 116/DIG. 42, 116/273, 116/271, 73/709, 73/56, 73/145
• US Class Current: 116/268
• CPC Class Codes: B01D 2279/60 for the intake of internal combustion engines or turbines intake systems for vehicles comprising filters F02M35/024
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/4254 Allowing or improving visual supervision, e.g. lamps, transparent parts, windows
• CPC Class Codes: B01D 46/54 Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms
• CPC Class Codes: F02M 35/09 Clogging indicators ; Diagnosis or testing of air cleaners sensors therefore F02M35/10373

Abstract

An air filter restriction indicating device communicating with the supply of air passing from an air filter to the air intake of an internal combustion engine. The indicating device senses a decrease in the supply of air drawn through the air filter by the engine based upon changes in the amount of vacuum in the negative side of the air supply, the amount of restriction being indicated by the movement of an indicating device. Improved means included in the indicating device senses the movement of the indicating device and progressively locks the indicating device into various indicating positions as the vacuum increases due to an increased restriction of the filter, so that the maximum reading of restriction achieved during engine operation remains visible to the operator or maintenance personnel even after the engine is turned off.

Claims

1. An improved restriction indicating device for an air filter used with an internal combustion engine where the improved indicating device is in communication with the air flowing from the air filter to the air intake of the internal combustion engine, the improved indicating device comprising:

a housing having a first end, a second end, and a side wall that includes a transparent portion;

the first end, the second end and the side wall defining an overall chamber in the housing;

a flexible diaphragm disposed within the housing, with the diaphragm having a central portion and having an edge portion secured to the housing so that the diaphragm divides the overall chamber into a first chamber, adjacent to the first end of the housing, and a second chamber, adjacent to the second end of the housing;

the central portion of the diaphragm being movable between an infold position wherein it is more closely adjacent to the second end of the housing and an outfold position wherein it is more closely adjacent to the first end of the housing;

an indicating member that is disposed within the first chamber in the housing and that is carried by and movable with the diaphragm;

the indicating member being visible through the transparent portion of the side wall of the housing at least as the diaphragm moves between its infold position and its outfold position;

means for permitting communication between the first chamber in the housing and the air flowing from the air filter to the air intake of the internal combustion engine;

means, including an opening in the second end of the housing, for permittng communication between the atmosphere and the second chamber in the housing;

a coil compression spring disposed in the first chamber of the housing, the compression spring being biased between the first end of the housing and the indicating member, with the bias of the compression spring being sufficient to move the diaphragm to its infold position when the vacuum in the first chamber is relatively low, as when a new air filter is initially used, but permitting the diaphragm to move from its infold position toward its outfold position in response to increases in the vacuum in the first chamber;

lock-up means for progressively locking the indicating member in the various positions which it attains within the first chamber as the diaphragm moves from its infold position to its outfold position and for maintaining the indicating member in its last such position even though there may thereafter be a subsequent decrease in the vacuum in the first chamber, the lock-up means including a tubular member carried by and movable with the central portion of the diaphragm, with the tubular member having a closed end that is adjacent to the first end of the housing and having an open end that is adjacent to the second end of the housing and that is in open communication with the second chamber;

the lock-up means also including an elongated locking member having a first end and a second end, the locking member being supported by the second end of the housing so as to permit movement of the first end of the locking member between a first position and a second position;

the first end of the locking member being disposed, when the first end of the locking member is in its first position, adjacent to the open end of the tubular member;

the second end of the locking member projecting from the second chamber through the opening in the second end of the housing;

the first end of the locking member and the open end of the tubular member having interengagable notches thereon that are adapted to be engaged when the first end of the locking member is in its first position, with engagement between the notches permitting the diaphragm to move from its infold position to its outfold position but preventing the diaphragm from returning to its infold position; and

means for selectively disengaging the interengagable notches so as to permit the diaphragm to return to its infold position when the vacuum in the first chamber is relatively low.

2. The improved restriction indicating device described in claim 1 which includes means for guiding the indicating member as the diaphragm moves between its infold position and its outfold position.

3. The improved restriction indicating device described in claim 2 wherein the guiding means includes a centrally disposed tubular hub portion mounted on the first end of the housing and projecting into the first chamber toward the second end of the housing;

and wherein the closed end of the tubular member projects into the first chamber and protrudes into and is closely slidable within the tubular hub portion as the diaphragm moves between its infold position and its outfold position.

4. The improved restriction indicating device described in claim 1 wherein the locking member is supported within the opening in the second end of the housing;

wherein the first end the locking member extends into the tubular member; and

wherein notches are formed on the first end of the locking member and are adapted to engage notches on the open end of the tubular member so as to progressively lock and maintain the indicating member in the last position which it attains as the diaphragm is moved from its infold position to its outfold position; and

wherein the disengaging means includes means for moving the locking member from its first position to its second position where there is no engagement between the interengagable notches.

5. The improved restriction indicating device described in claim 4 wherein the second end of the locking member extends through the opening in the second end of the housing and projects from the housing;

and wherein the locking member is pivotable about a portion of the side of the opening in the second end of the housing so that the first end of the locking member moves laterally from its first position to its second position.

6. The improved restriction indicating device described in claim 5 wherein a second compression spring is disposed between the projecting second end of the locking member and the second end of the housing and biases the first end of the locking member to its first position;

wherein movement of the second end of the locking member toward the second end of the housing, against the bias of the second spring, causes the locking member to pivot about said portion of the side of the opening in the second end of the housing so as to move the first end of the locking member from its first position to its second position.

7. The improved restriction indicating device described in claim 6 which includes means for guiding the indicating member as the diaphragm moves between its infold position and its outfold position;

and wherein the opening in the second end of the housing is centrally disposed.

8. The improved restriction indicating device described in claim 7 wherein the guiding means includes a centrally disposed tubular hub portion mounted on the first end of the housing and projecting into the first chamber toward the second end of the housing;

wherein the closed end of the tubular member projects into the first chamber and protrudes into and is closely slidable within the tubular hub portion as the diaphragm moves between its infold position and its outfold position; and

wherein the tubular hub portion and the tubular hub are axially aligned.