Patent Description:
Liquids often carry particulate matters or impurities within them. In many instances, it is desirable to partially or completely remove these impurities from the liquid. For example, any fuel being used for power supply, or any lubricant being used for heat and wear management. The impurities, should they reach the internal workings of the various mechanisms involved, can cause substantial damage thereto. It is therefore preferred, for such systems, to remove impurities from the fuel/lubricant before supplying them.

The design of a liquid filter must fulfill the filtration quality criteria set by the user and the rate of filtration criteria required by the various mechanisms. The most challenging design problem which affects the efficiency of the liquid filters is the layout of the flow connections. Typically, flow (inlet and outlet) connections of the liquid filter are found to be either from the top, from the bottom, or side along with top or bottom of the filter volume.

Traditionally, filters having foregoing flow connections may not cater to such applications where flow is in axial direction of filter with opposite need of openings. Similarly, liquid filters with conventional designs may hamper functionalities such as flow to filter, resistance to normal flow, priming requirements etc. in situations where flow is in axial direction of filter with opposite need of openings. Also, drawing fuel in axial flow situation is affected severely because of least fuel contained condition within housing of the filter.

The <CIT> discloses a filter element comprising a tubular member with a longitudinal axis. This tubular member includes a partition extending longitudinally within it, partially defining a first and a second chamber. The partition prevents fluid flow communication between these two chambers. At one end portion, the tubular member has an inlet port for fluid flow into the first chamber and partially defines an outlet port for fluid flow out of the second chamber. Additionally, the tubular member features outlet apertures facilitating fluid flow out of the first chamber and inlet apertures allowing fluid flow into the second chamber. The tubular member has an exterior wall extending longitudinally, with the outlet port being an aperture in this wall. A cover portion extends from the partition at the end portion, partially covering the longitudinal end of the second chamber. This cover portion is designed to substantially prevent fluid from flowing directly into the second chamber without first passing through the first chamber. The filter element also includes a filter medium with one portion located exterior and adjacent to the outlet apertures, and another portion located exterior and adjacent to the inlet apertures. The filter element's design ensures that fluid passing through it, from the inlet port to the outlet port, must flow through both the first and the second chambers.

The <CIT> discloses an encapsulated filter cartridge assembly adapted for reception within an elongated cartridge housing of a filtration system. The assembly comprises an elongated filtration medium, a connector head, an outer shell surrounding the filtration medium, and an expansion joint monolithically formed in the outer shell to facilitate expansion within the cartridge housing. Further, an elongated axial conduit tube extends through a central bore of the filter element, from an upper end cap to a lower end cap to conduct contaminated fluid from the inlet port of filter head into filter cartridge. The outer shell extends axially from the connector head and encapsulates the filtration medium. The expansion joint is defined by an undulated region with circumferentially or axially disposed undulations to allow radial or axial expansion of the outer shell. The filtration medium can be a pleated filter element with an axial bore, and the connector head includes inlet and outlet flow ports. The outer shell is made of a substantially rigid plastic material.

The <CIT> discloses a filter assembly comprising a filter cartridge with a floating seal design that compensates for misalignment between components. Inside the filter cartridge cavity, a dual center post extends from the filter head, which includes an inner center post and an outer center post surrounding the inner center post. The filter cartridge includes filter media, end plates, a fixed seal around the outer center post, and a floating seal around the inner center post. The floating seal has a gasket retained by a retainer body that can radially move within an opening in the end plate, allowing the seal to self-align with the inner center post. The amount of compensation provided by the floating seal depends on factors like the size of the gasket and the gap between the retainer body and the end plate opening. The filter assembly has an inlet port supplying unfiltered fluid to an outer cavity, which then flows through the filter media into an inner cavity before exiting through an outlet port.

Therefore, there is a need for a more cost and energy efficient liquid filter which can maintain consistent delivery in those applications where flow connections (inlet & outlet) are in axial direction of filter with opposite need of openings.

Before the present invention relating to liquid filter for fuel or lubricant filtration are described, it is to be understood that this application is not limited to the particular system(s) and methodologies described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the implementations or versions or embodiments only and is not intended to limit the scope of the present invention. This summary is provided to introduce aspects related to a liquid filter for fuel or lubricant filtration. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the present invention.

In one embodiment, a liquid filter for fuel or lubricant filtration is provided. The liquid filter includes a housing having a hollow interior, a first open end forming a filter inlet to allow the ingress of unfiltered fluid, and a second open end forming a filter outlet to allow the egress of filtered fluid. The liquid filter further includes a pleated filter block placed within the hollow interior of the housing. The pleated filter block having a hollow interior cavity wherein the hollow interior cavity of the pleated filter block having a suction tube and a pickup tube placed therein. In this respect, the pickup tube includes an inlet and an outlet such that the inlet of the pickup tube is coupled to the first open end of the housing to allow the passage of unfiltered fluid from the inlet to the outlet. Further, the suction tube includes an inlet and an outlet, wherein the inlet is placed within the hollow interior cavity of the pleated filter block and the outlet of the suction tube is coupled to the second open end of the housing such that the inlet of the suction tube allows the passage of filtered fluid from the hollow interior cavity of the pleated filter block to the filter outlet.

In another embodiment, a liquid filter for fuel or lubricant filtration is provided. The liquid filter includes a housing extending along an axis and defining an interior. The housing includes a top end cap including an outlet for filtered liquid, and a bottom end cap including an inlet for dirty liquid. The liquid filter further includes a center tube positioned centrally in the interior of the housing and extending along the axis. The center tube includes a pickup tube integrated inside the center tube and extending from the inlet of the bottom end cap to near the top of the housing for permitting axial inward flow of dirty liquid. The center tube further includes a suction tube integrated inside the center tube and extending from near the bottom of the center tube for drawing filtered liquid and supplying to the outlet of the top end cap. Further, the center tube includes a holding structure integratedly surrounding both the pickup tube and the suction tube, and defining an exterior wall configured to allow flow of the filtered liquid inside the center tube from surroundings. Furthermore, the liquid filter includes a pleated filter block configured to attach to the holding structure and surround the center tube such that dirty side is facing the housing for receiving the inward flow of dirty liquid from near the top of the housing, and clean side is facing the exterior wall of the holding structure.

In another embodiment, the pleated filter block has a cylindrical or frustoconical shape.

In yet another embodiment, the outer side of the pleated filter block is a dirty side of the pleated filter block.

In yet another embodiment, the inner side of the pleated filter block is a clean side of the pleated filter block.

In yet another embodiment, the pleated filter block is configured to removably attach to the holding structure.

In yet another embodiment, the pleated filter block is a spin-on type pleated filter block.

In yet another embodiment, the top end cap, which can also be referred as "first open end", and the bottom end cap, which can also be referred as "second open end", of the housing are integratedly formed in one piece with the housing.

The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure; however, the disclosure is not limited to the specific system/ apparatus or method disclosed in the document and the drawings.

In the above accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent.

Further, the figures depict various embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.

Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although a liquid filter for fuel or lubricant filtration, similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, liquid filter for fuel or lubricant filtration is now described.

In one aspect, embodiments of the present disclosure provide a liquid filter with axial inlet flow and axially opposite outlet flow. In another aspect, embodiments of the present disclosure provide a method of assembling a liquid filter with axial inlet flow and axially opposite outlet flow. In yet another aspect, embodiments of the present disclosure provide a method of servicing a liquid filter with axial inlet flow and axially opposite outlet flow.

The liquid filter includes a housing having a hollow interior, a first open end forming a filter inlet to allow the ingress of unfiltered fluid, and a second open end forming a filter outlet to allow the egress of filtered fluid. The liquid filter further includes a pleated filter block placed within the hollow interior of the housing.

The pleated filter block having a hollow interior cavity wherein the hollow interior cavity of the pleated filter block having a suction tube and a pickup tube placed therein.

In this respect, the pickup tube includes an inlet and an outlet such that the inlet of the pickup tube is coupled to the first open end of the housing to allow the passage of unfiltered fluid from the inlet to the outlet. Further, the suction tube includes an inlet and an outlet, wherein the inlet is placed within the hollow interior cavity of the pleated filter block and the outlet of the suction tube is coupled to the second open end of the housing such that the inlet of the suction tube allows the passage of filtered fluid from the hollow interior cavity of the pleated filter block to the filter outlet.

In another embodiment, a liquid filter for fuel or lubricant filtration is provided. The liquid filter includes a housing extending along an axis and defining an interior, a center tube positioned centrally in the interior of the housing and extending along the axis, and a pleated filter block configured to surround the center tube.

The housing includes a top end cap, which can also be referred as "first open end", with an outlet for filtered liquid and a bottom end cap, which can also be referred as "second open end", with an inlet for dirty liquid. The first open end and the second open end of the housing are integratedly formed in one piece with the housing.

The center tube includes a pickup tube integrated inside the center tube, a suction tube integrated inside the center tube, and a holding structure integratedly surrounding both the pickup tube and the suction tube. The pickup tube extends from the inlet of the bottom end cap to near the top of the housing for permitting axial inward flow of the dirty liquid. The suction tube extends from near the bottom of the center tube to the outlet of the top end cap for drawing and supplying filtered liquid. The holding structure defines an exterior wall configured to allow flow of the filtered liquid inside the center tube from surroundings.

The description of above mentioned two different embodiments provides a clarity on the subject matter that the center tube is not an essential part of the claimed liquid filter. The option of the center tube can be easily eliminated by having a hollow interior cavity in the pleated filter block. Thus, hollow interior cavity of the pleated filter block can easily accommodate a suction tube and a pickup tube which are placed therein.

With the description of the above-mentioned different embodiments, it is to be noted that the present disclosure substantially eliminates, or at least partially address, problems in the prior art, and assist the filter manufacturers, consumers and suppliers.

Further, various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments.

Referring now to the drawings, particularly by their reference numbers, <FIG> is a perspective view of a liquid filter <NUM> to filter fuel or lubricant, in accordance with an embodiment of the present claimed subject matter. The liquid filter <NUM> includes a housing <NUM> extending along the vertical axis XX'. As may be seen, the housing <NUM> has a cylindrical shape and includes a top end cap <NUM>, which can also be referred as "first open end", and a bottom end cap <NUM>, which can also be referred as "second open end", provided at both ends.

In an embodiment, the top end cap <NUM> and the bottom end cap <NUM> are integratedly formed in one piece with the housing <NUM>. The top end cap <NUM> includes an outlet <NUM> for allowing outflow of filtered liquid from the housing <NUM>. In an embodiment, a hand priming pump <NUM> is functionally attached to the outlet <NUM> of the top end cap <NUM> for easing priming. The bottom end cap <NUM> includes an inlet <NUM> for allowing inflow of dirty liquid inside the housing <NUM>. Further, it is to be noted that that the <FIG> merely an example. A person skilled in the art will recognize many variations, alternatives, and modifications of the embodiments of the present claimed subject matter.

<FIG> depicts cross-section of the liquid filter <NUM> in an assembled state, in accordance with an embodiment of the present claimed subject matter. Two different types of arrows are used to depict inflow of dirty liquid and outflow of filtered liquid. In an embodiment, the liquid filter <NUM> includes the housing <NUM> extending along the vertical axis XX' and defining an interior <NUM> between the top end cap <NUM> (first open end) and the bottom end cap <NUM> (second open end). As depicted, a center tube <NUM> is positioned centrally in the interior <NUM> of the housing <NUM> about a pivot region <NUM> of the bottom end cap <NUM>. The center tube <NUM> extends along said axis XX' upto the top end cap <NUM>.

The center tube <NUM> includes a pickup tube <NUM> integrated inside the center tube <NUM>. The pickup tube <NUM> extends from the inlet <NUM> of the bottom end cap <NUM> to near the top of the housing <NUM> for permitting axial inward flow of the dirty liquid, according to an embodiment of the present disclosure. As shown, the center tube <NUM> includes a suction tube <NUM> integrated inside the center tube <NUM>. The suction tube <NUM> extends from near the bottom of the center tube <NUM> to the outlet <NUM> of the top end cap <NUM> for drawing and supplying filtered liquid, in accordance with an embodiment of the present disclosure. As depicted further, the center tube <NUM> includes a holding structure <NUM> integratedly surrounding both the pickup tube <NUM> and the suction tube <NUM>.

In an embodiment, the holding structure <NUM> defines an exterior wall <NUM> configured to allow flow of the filtered liquid inside the center tube <NUM> from surroundings. In an embodiment, the exterior wall <NUM> has a helical shape.

As depicted in the present embodiment, the liquid filter <NUM> includes a pleated filter block <NUM>. The pleated filter block <NUM> is attached to the holding structure <NUM> in a manner such that dirty side DS is facing the housing <NUM> for receiving the inward flow of dirty liquid from near the top of the housing <NUM>. Further, clean side CS of the pleated filter block <NUM> faces the exterior wall <NUM> of the holding structure <NUM>.

In another embodiment, the pleated filter block <NUM> is a spin-on type pleated filter block. In yet another embodiment, the pleated filter block <NUM> has a cylindrical or frustoconical shape.

In yet another embodiment, the outer side of the pleated filter block <NUM> is a dirty side DS of the pleated filter block <NUM>.

In yet another embodiment, the inner side of the pleated filter block <NUM> is a clean side CS of the pleated filter block <NUM>.

In yet another embodiment, the pleated filter block <NUM> is configured to removably attach to the holding structure <NUM>.

Further, it is to be noted that that the <FIG> merely an example. A person skilled in the art will recognize many variations, alternatives, and modifications of the embodiments of the present claimed subject matter.

<FIG> illustrates a flow-chart depicting various steps for a method <NUM> of assembling the liquid filter <NUM>, in accordance with the embodiments of the present claimed subject matter.

As shown, the method <NUM> of assembling the liquid filter <NUM> includes a first step <NUM> of arranging the center tube <NUM> along the axis XX' of the housing <NUM> such that the pickup tube <NUM> and the suction tube <NUM> are sealingly integrated with the bottom end cap <NUM>. The method <NUM> includes a second step <NUM> of locking the center tube <NUM> about the pivot region <NUM> of the bottom end cap <NUM>. In an embodiment, the center tube <NUM> is locked by rotating about the pivot region <NUM> of the bottom end cap <NUM>. The method <NUM> also includes a third step <NUM> of attaching the pleated filter block <NUM> to the holding structure <NUM> such that the pleated filter block <NUM> surrounds the center tube <NUM>, and the dirty side DS is facing the housing <NUM> and clean side CS is facing the center tube <NUM>. The method <NUM> further includes a fourth step <NUM> of applying force to an exposed portion of the housing <NUM> for locking the top end cap <NUM> and the bottom end cap <NUM> into sealing engagement with the housing <NUM>.

<FIG> illustrates a flow-chart depicting various steps for a method <NUM> of servicing the liquid filter <NUM>, in accordance with the embodiments of the present claimed subject matter.

As shown, the method <NUM> of servicing the liquid filter <NUM> includes a first step <NUM> of applying force to an exposed portion of the housing <NUM> for unlocking the top end cap <NUM> from the housing <NUM>. The method <NUM> includes a second step <NUM> of separating the pleated filter block <NUM> surrounding the holding structure <NUM>. The present method <NUM> also includes a third step <NUM> of attaching a replacement pleated filter block (not shown) to the holding structure <NUM> such that the replacement pleated filter block surrounds the center tube <NUM>, and the dirty side DS is facing the housing <NUM> and clean side CS is facing the center tube <NUM>. The method <NUM> further includes a fourth step <NUM> of applying force to an exposed portion of the housing <NUM> for locking the top end cap <NUM> into sealing engagement with the housing <NUM>.

With reference to <FIG> and according to an alternative embodiment, the method <NUM> of servicing the liquid filter <NUM> may include a first step <NUM> of applying force to an exposed portion of the housing <NUM> for unlocking the bottom end cap <NUM> from the housing <NUM>. The method <NUM> includes a second step <NUM> of separating the pleated filter block <NUM> surrounding the holding structure <NUM>. The alternative embodiment of the method <NUM> also includes a third step <NUM> of attaching a replacement pleated filter block (not shown) to the holding structure <NUM> such that the replacement pleated filter block surrounds the center tube <NUM>, and the dirty side DS is facing the housing <NUM> and clean side CS is facing the center tube <NUM>. The method <NUM> further includes a fourth step <NUM> of applying force to an exposed portion of the housing <NUM> for locking the bottom end cap <NUM> into sealing engagement with the housing <NUM>.

Further, it is to be noted that the embodiments of the present disclosure can be used for various purposes, including, though not limited to, manufacturing and servicing of liquid filters.

Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "consisting of", "have", "is" used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

Claim 1:
A liquid filter (<NUM>) comprising:
a housing (<NUM>) extending along an axis and defining an interior (<NUM>), the housing (<NUM>) including:
a top end cap (<NUM>) including an outlet (<NUM>) for filtered liquid, and a bottom end cap (<NUM>) including an inlet (<NUM>) for dirty liquid;
a center tube (<NUM>) positioned centrally in the interior (<NUM>) of the housing (<NUM>) and extending along said axis, the center tube (<NUM>) comprising:
a pickup tube (<NUM>) integrated inside the center tube (<NUM>) and extending from the inlet (<NUM>) of the bottom end cap (<NUM>) to near the top of the housing for permitting axial inward flow of dirty liquid,
a suction tube (<NUM>) integrated inside the center tube (<NUM>) and extending from near the bottom of the center tube (<NUM>) for drawing filtered liquid and supplying to the outlet (<NUM>) of the top end cap (<NUM>), and
Characterized in that it further comprises
a holding structure (<NUM>) integratedly surrounding both the pickup tube (<NUM>) and
the suction tube (<NUM>), and defining an exterior wall configured to allow flow of the filtered liquid inside the center tube (<NUM>) from surroundings; and
a pleated filter block (<NUM>) configured to attach to the holding structure (<NUM>) and
surround the center tube (<NUM>) such that dirty side is facing the housing (<NUM>) for receiving the inward flow of dirty liquid from near the top of the housing (<NUM>), and clean side is facing the exterior wall of the holding structure (<NUM>).