US 4,153,003 A · Filter condition indicator

Abstract

A pressure differential indicator for indicating a change in a fluid pressure differential across a component in a fluid system, such as an oil filter, has piston means, means for communicating fluid pressures of said system upstream and downstream of said component to opposite sides of said piston means, respectively, and differential means associated with the piston means for normally balancing the resultant forces of said pressure on opposite sides of said piston means at a given predetermined pressure differential across said component whereby said piston means is responsive to an increase or decrease in the pressure differential above or below said predetermined differential pressure to indicate a clean or clogged filter condition. Means are provided for holding the piston means in its last position upon relief of said first and second pressures to indicate the operating filter condition when the system is not operating. In alternative embodiments, the indicator includes "kicker" means to start its motion, is responsive at all times to pressure differential above or below a predetermined value and includes a number of embodiments of adaptors to accommodate its introduction into fluid systems.

Claims23

Dependent claims

A pressure differential indicator comprising:

first and second piston means in first and second chambers, respectively,
means to subject said first and second piston means to first and second pressures respectively,
interconnecting means extending into each of said first and second chambers and connected between said first and second piston means, for requiring that the pressure force produced by said first pressure on said first piston means to enable said first piston means to move said first and second piston means together with said interconnecting means be a predetermined amount larger than the pressure force produced by said second pressure on said second piston means to enable said second piston means to move said first and second piston means together with said interconnecting means, and
kicker means provided in said first chamber for sealing off a portion of said first piston means from the pressure in said first chamber to reduce the area of said first piston means subjected to said first pressure when said first piston means is seated therein and only until said first piston means has begun to move said first and second piston means together with said interconnecting means and to thereafter no longer reduce said area, whereby said first piston means moves said first and second piston means together with said interconnecting means with a snap action.

1 more element

In a pressure differential indicator for indicating a rise in a fluid pressure differential across a filter in a fluid system when in normal operation, due only to contamination build up and wherein said indicator includes movably mounted piston means and means for communicating fluid pressures of said system upstream and downstream of said filter to first and second piston surfaces of said piston means which are in opposed force transmitting relationship, the improvement comprising the provision of:

differential means for giving said second piston surface a hydrostatic advantage over said first pistion surface in said opposed force transmitting relationship for normally unbalancing the resultant forces of said pressures on said piston means in favor of that applied by said second surface to hold said piston means in a given first clean filter indicating position under varying system pressures operating with a clean filter condition, said differential means including means for causing movement of said piston means to a second caution contamination filter indicating position only when the resultant forces on said piston means are substantially balanced due to increases in the pressure drop across said filter of a given predetermined increased amount indicative of a predetermined amount of filter contamination warranting replacement of said filter and to a third dirty filter indicating position on further increases in said pressure drop, whereby said piston means is movably responsive relative said second caution position to an increase or decrease in the pressure differential across said filter due only to filter contamination above or below said predetermined increased amount of pressure differential which balances said resultant forces of said pressures on said piston means first and second surfaces, respectively, and
means for giving a visually observable indication of the position of said piston means,
wherein said piston means includes two pistons, each having one of said surfaces in communication with said upstream and downstream pressures, and said differential means comprises the provision of:
interconnecting means between said pistons to provide simultaneous motion therefor and including a pivoted connecting rod extending between said pistons and wherein the lever arm of said rod from its pivot to the piston having said second surface which is exposed to downstream pressure is longer than that relative to the other piston.

1 more element

differential means for giving said second piston surface a hydrostatic advantage over said first pistion surface in said opposed force transmitting relationship for normally unbalancing the resultant forces of said pressures on said piston means in favor of that applied by said second surface to hold said piston means in a given first clean filter indicating position under varying system pressures operating with a clean filter condition, said differential means including means for causing movement of said piston means to a second caution contamination filter indicating position only when the resultant forces on said piston means are substantially balanced due to increases in the pressure drop across said filter of a given predetermined increased amount indicative of a predetermined amount of filter contamination warranting replacement of said filter and to a third dirty filter indicating position on further increases in said pressure drop, whereby said piston means is movably responsive relative said second caution position to an increase or decrease in the pressure differential across said filter due only to filter contamination above or below said predetermined increased amount of pressure differential which balances said resultant forces of said pressures on said piston means first and second surfaces, respectively;
means for giving a visually observable indication of the position of said piston means;
and
means are provided for holding said movably mounted piston means in its system operating position it assumes due to said system pressures upon reduction of said pressures.

1 more element

In a pressure differential indicator for indicating a rise in a fluid pressure differential across a filter in a fluid system when in normal operation, due only to contamination build up and wherein said indicator includes moveably mounted piston means and means for communicating fluid pressures of said system upstream and downstream of said filter to first and second piston surfaces, respectively, of said piston means which are in opposed force transmitting relationship in first and second chambers the improvement comprising the provision of:

differential means for giving said second piston surface a mechanical advantage over said first piston surface in said opposed force transmitting relationship for normally unbalancing the resultant forces of said pressures on said piston means in favor of that applied by said second surface under varying system pressures operating with a clean filter condition and by an amount whereby the forces on said piston means are balanced under varying system pressures when the contamination of said filter increases the pressure drop thereacross by a given predetermined increased amount, whereby said piston means is responsive to an increase or decrease in the pressure differential across said filter due only to filter contamination above or below said predetermined increased amount of pressure differential which balances said resultant forces of said pressures on said piston means;
means for giving a visually observable indication of the movement of said piston means;
means for holding said moveably mounted piston means in its system operating position it assumes due to said system pressures upon reduction of said pressures;
and
wherein said means for holding said piston means in its system operating position comprises the provision of an assembly of two separate members biased apart and means for engaging the walls of a surrounding chamber within which said piston means is positioned and which is operated to so engage said walls by the said members in their biased apart position and released when said members are subjected to said pressures.

2 more elements

A pressure differential indicator comprising:

first and second piston means,
means to subject said first and second piston means to first and second pressures respectively;
a housing having cylinder means to mount said first and second piston means in a side-by-side tandem arrangement;
interconnecting means between said first and second piston means and including differential force means selectively provided to require that the pressure force produced by said first pressure on said first piston means to enable said first piston means to move said first and second piston means together with said interconnecting means be a predetermined amount larger than the pressure force produced by said second pressure on said second piston means to enable said second piston means to move said first and second piston means together with said interconnecting means,
said interconnecting means comprising a cross beam having each of its ends operatively co-operable with one of said first and second piston means;
and
means to pivotally mount said cross beam intermediate its ends in said housing the configurations and locations of said cross beam, said piston means, and the pivot point of said cross beam in said housing being provided so that a portion of one or the other of said first and second piston means is exposed out of said housing at an one instant.

4 more elements

A pressure differential indicator comprising:

first and second piston means,
means to subject said first and second piston means to first and second pressures respectively,
interconnecting means between said first and second piston means, and including differential force means selectively provided to require that the pressure force produced by said first pressure on said first piston means to enable said first piston means to move said first and second piston means together with said interconnecting means be a predetermined amount larger than the pressure force produced by said second pressure on said second piston means to enable said second piston means to move said first and second piston means together with said interconnecting means,
a housing means to mount said first and second piston means and said interconnecting means, in said housing;
said first and second pressures comprising the upstream and downstream pressures of a filter member located in a circulating pressurized fluid system, and said means to subject said piston means to said pressures comprising adapter means interposed between said indicator housing and said filter member;
wherein said filter member is of the spin-on type, said adapter means comprising an adapter member having one side for connection to the engine which simulates a normal spin-on filter, and its opposite side for connection to the filter which simulates the normal engine connection, said adapter means further comprising a ring portion surrounding said adapter member to permit rotation of said adapter member therein, and a throat portion for interconnecting said ring portion with said indicator housing and passageway means forming part of said pressure subjecting means formed in said adapter member and said throat portion to tap into the flow of lubricating oil through said adapter member to and from said filter to deliver said pressures to said indicator means, and fluid seals interposed one between said adapter means and engine and another between said adapter means and said filter.

3 more elements

A pressure differential indicator comprising:

first and second piston means,
means to subject said first and second piston means to first and second pressures respectively,
interconnecting means between said first and second piston means and including differential force means selectively provided to require that the pressure force produced by said first pressure on said first piston means to enable said first piston means to move said first and second piston means together with said interconnecting means be a predetermined amount larger than the pressure force produced by said second pressure on said second piston means to enable said second piston means to move said first and second piston means together with said interconnecting means, and a body of generally elongated cylindrical shape comprising a pair of bores extending inwardly towards the opposite ends thereof, said piston means comprising a pair of piston members mounted one in each of said bores, an interconnecting rod extending between said pistons through a suitably formed opening in the wall of said body between said bores and rigidly interconnecting said pistons, the overall length of said pistons and interconnecting rods being longer than the overall length of said body, said first and second pressures both being less than atmospheric pressure and said indicator being exposed to atmospheric pressure on the outside thereof, said first and second piston means each comprising a piston member of stepped construction, and retainer plates mounted in each end of said body for cooperation with the step in said piston members to define the outermost limit of motion of each of said piston members.

Dependencies are inferred from the claim text.

Filter condition indicator

Life of this patent

Filter condition indicator

Life of this patent

Abstract

Claims23