Air filter front end plate, air filter element and air filter device

Abstract

An air filter front end plate (1) configured to close a front end portion (102) of a hollow air filter media pack (101), the front end plate comprising a bowl-shaped member (2) and a flange member (3) positioned along a periphery (4) of the bowl-shaped member (2), the bowl-shaped member comprising a connection point (5), the connection point is located at the center of the bowl-shaped member and is configured to be connected to a front end portion (132) of a mounting bracket (131) in the air filter device, the bowl-shaped member (2) extends from a front end portion (21) of the air filter front end plate towards a rear end portion (22) and is configured to be at least partially inserted into a front end portion opening (102) of a hollow air filter medium pack (101), and wherein the bowl-shaped member (2) is configured to be connected to the front end portion (132) of the mounting bracket (131). The bowl-shaped member (2) has an inflexion shape with a first curved portion (7) positioned closer to the front end portion (21) and a second curved portion (8) positioned closer to the rear end portion (22), where the first curved portion (7) has a convex shape with respect to a centerline passing through the air filter front end plate and the second curved portion (8) has a convex shape with respect to a centerline passing through the air filter front end plate. The second curved portion (8) has a concave shape with respect to the centre line, whereby the connection point (5) is located in a position in front of the second curved portion (8). The present disclosure also relates to a pressure indicator gasket, a pressure indicator assembly, a front end plate, an air filter cartridge (110) and an air filter device (200).

Description

Technical Field

[0001] The present disclosure relates to an air filtration device, and particularly to a front end plate of an air filter, an air filter element, and an air filter device. The present disclosure also relates to a pressure indicator gasket, a pressure indicator assembly, a front end plate of an air filter, an air filter element, and an air filter device including the pressure indicator gasket. Background Art

[0002] Hollow air filters typically include some kind of support device for holding a hollow air filtration media pack in place against a base plate or tube plate in an air filter device, and the filter is typically mounted on a mounting frame to hold it in place. Importantly, the air filter is easy to install in the air filter device. However, there has been a continuing desire to improve performance and reduce costs in air filtration, and thus there is a need for an improved air filter that exhibits improved performance and is easy to manufacture and install. Summary of the Invention

[0003] The present disclosure relates to a front end plate of an air filter configured to enclose a front end portion of a hollow air filtration media pack. The front end plate includes a bowl-shaped member and a flange member positioned along a periphery of the bowl-shaped member. The bowl-shaped member includes a connection point located at a center of the bowl-shaped member and configured to connect to a front end portion of a mounting frame in an air filter device. The bowl-shaped member extends from a front end portion of the front end plate of the air filter toward a rear end portion and is configured to be at least partially inserted into an opening at the front end portion of the hollow air filtration media pack. And wherein the bowl-shaped member has a reverse-curved shape with a first curved portion positioned closer to the front end portion and a second curved portion positioned closer to the rear end portion, wherein the first curved portion has a convex shape relative to a center line passing through the front end plate of the air filter, and the second curved portion has a concave shape relative to the center line, whereby the connection point is located in a position in front of the second curved portion.

[0004] The second curved portion of the bowl-shaped member may be suitably configured to form a recess on a rear side portion of the front end plate of the air filter, and the recess is adapted to receive a connection member attached to the mounting frame.

[0005] The connection point in the bowl-shaped member may suitably include an opening and a connection device located on a front side portion of the bowl-shaped member. The connection device of the front end plate of the air filter includes an elastic compression element and a pressure cap (pressure gasket), and the elastic compression element is arranged between the bowl-shaped member and the pressure cap. The elastic compression element may include two or more protruding portions extending in a forward direction from a base portion.

[0006] The resilient compression element advantageously has a central opening configured to receive a connecting member to be inserted through an opening in the bowl-shaped member, and the resilient compression element can suitably be an integral one-piece element, preferably an integral one-piece element made of an elastomeric polymeric material.

[0007] The resilient compression element can advantageously be configured to interlock with the edge of the opening in the bowl-shaped member for attachment to the bowl-shaped member and is preferably obtained by co-injection molding.

[0008] The pressure cap preferably has a central opening configured to receive the connecting member and can also advantageously include one or more indicator protrusions configured to be pushed in a forward direction by the compression element when the pressure applied on the pressure cap and the compression element reaches a predetermined pressure limit.

[0009] The bowl-shaped member preferably includes a ramp portion adjacent to the flange member, the ramp portion being configured to be inserted into the front-end opening and fitted into the front-end opening of an air filter medium support cage disposed inside the hollow air filter medium pack.

[0010] The flange member can suitably include an air filter medium holding recess configured to receive the front end of the hollow air filter medium pack.

[0011] The present disclosure also relates to an air filter element, which includes the above-described air filter front plate, air filter medium support cage, hollow air filter medium pack, and rear plate, wherein the air filter medium support cage is disposed inside the hollow air filter medium pack, and the air filter front plate is inserted into the front-end opening of the air filter medium support cage and the front-end opening of the air filter medium pack.

[0012] In addition, the present disclosure also relates to an air filter device, which includes an air filter element, a mounting frame, and an air filter base plate having an air flow opening, wherein the filter element is fastened to the mounting frame, and the rear plate faces the base plate, and wherein the front end of the mounting frame is connected to the air filter front plate of the filter element at a connection point. A second filter element having an open front plate can be disposed between the air filter element and the base plate. The mounting frame is preferably a tripod.

[0013] The present disclosure also relates to a pressure indicator washer, which includes a main part having a central opening configured to receive a connecting rod of a mounting bracket. The main part has a front side and a rear side. The indicator washer further includes at least one indicator protrusion provided in the main part, and the indicator protrusion includes a contact portion protruding from the rear side of the main part. The indicator protrusion is preferably configured to be pushed out from the front side of the main part when the pressure applied to the rear side of the contact portion reaches a predetermined pressure limit. The indicator protrusion preferably may include a weakened profile member, and the weakened profile member is preferably a perforated line or a weakened line having an intermediate bridging member. The indicator protrusion is preferably connected to the pressure washer through a hinge portion. The protruding contact portion of the indicator protrusion and the weakened profile member of the indicator protrusion are advantageously made of different materials. The pressure indicator washer preferably includes a contact area on the front side of the main part, and the contact area surrounds the central opening and is configured to receive the force applied by a fastening element attached to the connecting rod during installation. The fastening element is preferably a nut screwed onto the connecting rod during installation. In some embodiments, the pressure indicator washer may include a plurality of pressure indicator protrusions.

[0014] The present disclosure also relates to a pressure indicator assembly, which includes the above-mentioned pressure indicator washer and a compression element having a central opening and at least one protruding element. The central opening of the compression element and the central opening of the pressure indicator washer are configured to receive a connecting rod of a mounting bracket. In this assembly, the pressure indicator washer is configured to be positioned on the compression element such that the central opening of the pressure indicator washer coincides with the central opening of the compression element during assembly, and at least one protruding element points to the rear side of the pressure indicator washer. The indicator protrusion of the pressure indicator washer has a position aligned with the position of at least one protruding element of the compression element. The compression element is preferably an elastic compression element.

[0015] The pressure indicator assembly preferably may include a base plate, which is adapted to be positioned on the rear side of the compression element opposite to the pressure indicator washer. The base plate has a central opening and preferably has a circumferential flange, and the circumferential flange is adapted to engage with the compression element during assembly. The pressure indicator washer may preferably include a circumferential flange, and the circumferential flange is adapted to engage with the compression element during assembly.

[0016] In addition, the present disclosure relates to a front plate of an air filter, which is configured to enclose a front end portion of a hollow air filter medium package. The front plate includes a central member and a flange member positioned along a periphery of the central member. The central member includes a connection point that is located at a center of the central member and is configured to be connected to a front end portion of a mounting bracket in an air filter device, wherein the pressure indicator gasket as described above is disposed at the connection point. Advantageously, the pressure indicator gasket is included in the pressure indicator assembly as described above.

[0017] The present disclosure also relates to an air filter element, which includes the above-described front plate of the air filter, a hollow air filter medium package, and a rear plate. The present disclosure also relates to an air filter device, which includes the air filter element, a mounting bracket, and an air filter base plate having an air flow opening. The filter element is fastened to the mounting bracket, and the rear plate faces the base plate. The front end portion of the mounting bracket is connected to the front plate of the air filter of the filter element at the connection point such that a connecting rod is inserted through a central opening of the pressure indicator gasket, and a fastening element is fastened relative to the connecting rod. The indicator protrusion is adapted to be pushed out from a front side portion of a main part of the pressure indicator gasket when the pressure applied to a rear side portion of a contact portion of the gasket reaches a predetermined pressure limit. A second air filter element may be disposed between the air filter element and the air filter base plate. The connecting rod is suitably a part of the mounting bracket, and the mounting bracket is preferably a tripod.

[0018] The present disclosure will become apparent from the following detailed description. The detailed description and exemplary embodiments disclose only preferred embodiments of the present disclosure by way of illustration. Those skilled in the art can understand that changes and modifications can be made within the scope of the present disclosure according to the guidance in the detailed description.

[0019] Therefore, it should be understood that the disclosure herein is not limited to the specific components of the device described, as such devices can vary. It should also be understood that the terms used herein are for the purpose of describing specific embodiments only and are not intended to be restrictive. It should be noted that, as used in the specification and the appended claims, unless the context clearly dictates otherwise, the articles "a", "an", "the", and "said" are intended to mean one or more of the elements. Thus, for example, a reference to "a unit" or "the unit" may include several devices and the like. In addition, the words "comprising", "including", "containing", and similar expressions do not exclude other elements or steps.

[0020] Detailed Description

[0021] The present disclosure relates to a front end plate of an air filter, which is configured to enclose a front end portion of a hollow air filter medium pack. The front end plate of the air filter is suitable for use in any type of hollow air filter and is particularly useful in a pulse filter, i.e., an air filter in which short compressed air pulses are periodically directed in a direction opposite to the main filtration direction for cleaning the filter. The filter medium pack can be of any suitable type and typically can be of a hollow structure, where a pleated filter medium pack extends circumferentially and the pleats extend in the longitudinal direction of the cage wall member.

[0022] The front end plate of the air filter according to the present disclosure is intended to allow the use of different construction materials in the filter element to be used and the mounting frame, where the filter element will be mounted in the air filter device by means of the mounting frame. The details and characteristics of the front end plate of the air filter will be described in more detail below.

[0023] Accordingly, the present disclosure also relates to an air filter element, which includes a front end plate of the air filter, an air filter medium support cage, a hollow air filter medium pack, and a rear end plate. Among them, the air filter medium support cage is arranged on the inner side portion of the hollow air filter medium pack, and the front end plate of the air filter is inserted into the front end opening of the air filter medium support cage and the front end opening of the air filter medium pack.

[0024] In addition, the present disclosure also relates to an air filter device, which includes an air filter element, a mounting frame, and an air filter base plate having air flow openings. Among them, the filter element is fastened to the mounting frame, and the rear end plate points to the base plate. And the front end portion of the mounting frame is connected to the front end plate of the filter element at the connection point. A gasket is preferably attached to the rear surface of the rear end plate to obtain proper sealing. The base plate can be part of a mounting frame or a tube plate. A second filter element having an open front end plate can be arranged between the air filter element and the base plate to form an air filter element assembly. The mounting frame is preferably a tripod to allow easy installation of the air filter element.

[0025] In the present disclosure, the terms "front" and "forward" refer to the position or direction at the closed end of the hollow air filter structure, for example, the position or direction located farthest from the base plate to which the air filter element is mounted. Similarly, the terms "rear" and "backward" refer to the position or direction opposite to the closed end of the hollow air filter structure, for example, the position or direction located closer to the base plate or the tube plate.

[0026] When the air filter element is installed in the air filter device, the installation device is used to apply tension between the front end plate and the base plate. The installation of the hollow air filter element typically uses an installation device including one or more steel rods or bars attached to an opening in the base plate, allowing air to enter or leave the filter. An example is a tripod mounting bracket, in which the bars are installed circumferentially at a uniform distance around the air passage opening. These bars converge into a central common section at the front end of the tripod and end at a single attachment point located centrally, at which an attachment member may be provided, preferably in the form of a threaded rod, but alternatively the attachment member may include a hook or other fastening device for securing the filter. When the air filter element is installed against the base plate, the attachment member may protrude through a hole in the front end plate so that the fastening device can be used to engage with the other half of a nut, rod hook or fastening mechanism. When the air filter element is installed onto the tripod by a threaded central rod, a nut is placed on the threaded rod and tightened, and the filter medium pack and the front end plate will press against the base plate to ensure that the filter element is fully supported and sealed to the base plate.

[0027] Another example is an installation rod having a threaded first end and a flange at the second end, and the installation rod passes through the front end of the filter element and through the front end plate and is inserted all the way into the rear end of the filter element of the filter element assembly, and the threaded first end is engaged with a threaded installation member attached to the air passage opening.

[0028] It is desirable to be able to use an air filter medium support cage made of plastic material in the air filter element to allow for efficient manufacturing and to be able to obtain very complex structures including various elements that can improve the performance of the air filter and reduce costs. However, during the operation of the air filter installation, the temperature may change greatly, and the metal parts and plastic parts may expand very differently with temperature changes. There are plastic materials with a thermal expansion coefficient similar to that of steel, but such plastic materials are relatively expensive. In order to be able to utilize different construction materials with different temperature expansion characteristics in the hollow air filter element and its installation device in the air filter device or housing, it is important to avoid excessive or insufficient sealing pressure between the filter element and the base plate and to avoid inelastic deformation of the filter element or the mounting bracket.

[0029] If the mounting bracket and the support cage in the filter element are made of the same material or materials with the same coefficient of thermal expansion, a seal will be maintained at varying temperatures. However, if the coefficients of thermal expansion are different, such as when the mounting means is made of steel rods and the support cage in the filter is made of plastic or a composite material, an adequate seal may not be maintained over a wide temperature fluctuation. In such a case where the coefficient of thermal expansion of the plastic or composite material is higher than that of steel, an increase in temperature will cause the mounting bracket to elongate less than the filter, and a decrease in temperature will cause the mounting means to contract less than the support cage in the filter. If the typical operating temperature is higher than the installation temperature, the length of the support cage in the filter will expand more than the length of the mounting bracket. This can result in additional stress on the filter element, and these stresses must be tolerated without causing damage. If the typical operating temperature is lower than the installation temperature, the filter will contract more than the mounting bracket, and the integrity of the filter seal may be affected, resulting in air bypass.

[0030] Accordingly, it is desirable to obtain an air filter element in which a filter media support cage made of plastic or a composite material, such as unreinforced ABS, can be used, and the air filter element can also be installed in an air filter device by means of a mounting bracket made of steel or other metal without the risk of filter element deformation or leakage.

[0031] The front end plate according to the present disclosure includes a bowl-shaped member and a flange member positioned along the periphery of the bowl-shaped member, and the bowl-shaped member includes a connection point located at the center of the bowl-shaped member and configured to connect to the front end portion of a mounting bracket in an air filter device. The bowl-shaped member extends from the front end portion of the air filter front end plate toward the rear end portion and is configured to be at least partially inserted into the front end opening of a hollow air filter media pack, and wherein the bowl-shaped member has a reverse-curved arcuate shape with a first curved portion positioned closer to the front end portion and a second curved portion positioned closer to the rear end portion, wherein the first curved portion has a convex shape relative to a center line passing through the air filter front end plate, and the second curved portion has a concave shape relative to the center line, whereby the connection point is located in a position in front of the second curved portion. When a certain degree of tension is applied to the connection point in the axial direction, the two curved portions allow the front end plate to bend, so that some additional forces generated due to high temperature thermal expansion can be absorbed by the bending of the reverse-curved arcuate shape rather than transmitted to the filter media support cage, where these additional forces may cause breakage. Accordingly, the front end cap can be made of rigid plastic but still be sufficiently flexible. Thus, when the temperature increases and the filter media support cage attempts to expand in size, the front end cap is capable of reversibly bending rather than simply pressing against the mounting nut and generating high stresses.

[0032] The second bending portion of the bowl-shaped member can be appropriately configured to form a recess on the rear side portion of the front end plate of the air filter. The recess is adapted to receive a connecting member attached to the mounting bracket and facilitates the self-centering of a connecting rod serving as an attachment member inserted from the rear side portion of the bowl-shaped member, making it easier to align with the mounting bracket, such as in the form of a tripod.

[0033] The connection point in the bowl-shaped member can appropriately include an opening and a connecting device on the front side portion of the bowl-shaped member. The connecting device of the front end plate of the air filter includes an elastic compression element and a pressure cover (pressure washer), and the elastic compression element is arranged between the bowl-shaped member and the pressure cover. In the present disclosure, the terms "pressure cover" and "pressure washer" are used interchangeably to refer to the same or similar components.

[0034] Both the elastic compression element and the pressure cover preferably have a central opening configured to receive a connecting member in the form of a connecting rod to be inserted through the opening in the bowl-shaped member.

[0035] The elastic compression element can include two or more protruding portions extending in the forward direction from the base portion to enhance the elasticity of the compression element, and the pressure cover or pressure washer can also advantageously include one or more indicator protrusions configured to be pushed in the forward direction by one or more of the protruding portions of the compression element when the tension pressure applied on the pressure cover and the compression element reaches a predetermined pressure limit, so as to move significantly from the first position to the second position, thereby reducing the risk of over-compression and simplifying the installation procedure.

[0036] The pressure cover is advantageously used in combination with the compression element as described herein, but can also be used independently without the compression element.

[0037] The pressure cover or pressure washer including the indicator protrusion can be appropriately used together with the front end plate including the bowl-shaped member as described herein, but can also be used in other applications, such as connecting to a conventional front end plate of a hollow air filter, or in any other application where it is important to avoid over-tightening of the threaded engagement between fastening elements. When installing a hollow air filter on a mounting bracket, such as a tripod for example, over-tightening may damage the mounting bracket in the worst case, which may thus lead to difficulties in installing a replacement filter or its damage. The indicator protrusion also facilitates the installation of the air filter because the person installing the filter can easily know when the fastening element has been sufficiently tightened, thus making the installation faster and more accurate.

[0038] A compression element including two or more protruding portions and a pressure cap or pressure washer having an indicator protrusion form a pressure indicator assembly, which can be used in many different applications in addition to the above examples related to the bowl-shaped front end plate. The compression element can be provided with a substantially flat rear surface, which can act as a stable base for the pressure indicator washer. The elastic compression element is preferably made of an elastic polymer material, preferably made of a thermoplastic elastomer material (TPE), such as thermoplastic polyurethane (TPU). The elastic compression element can be suitably made as an integral one-piece element and can be configured to interlock with the edge of the opening in the bowl-shaped part to be attached to the bowl-shaped part. Thus, the elastic compression element can also act as a washer between the bowl-shaped part and the connecting member (connecting rod). The elastic compression element can preferably be obtained by co-injection molding with the front end plate, which is the bowl-shaped part of the front end plate in the above embodiment.

[0039] The elastic compression element can act as a spring member in the front end plate and is compressed to a certain stress during initial installation. At low temperatures, since the filter medium support cage shrinks and the stress in the elastic compression element will decrease, resulting in an increase in the size of the elastic compression element and occupying some gaps to prevent leakage between the filter element and the base plate. At high temperatures, since the filter medium support cage expands, the stress in the elastic compression element will increase, resulting in the elastic compression element being compressed more. This additional compression in the elastic compression element provides a little more expansion space for the filter medium support cage, thus reducing the net force it bears.

[0040] Polymer materials, such as thermoplastic elastomers, may also be affected by temperature. However, since the elastic compression element is relatively small in the length direction compared to the filter medium support cage, the expansion of the elastic compression element in the length direction will basically not affect the performance of the filter element. The fact that polymer materials including thermoplastic elastomers become harder at lower temperatures can actually be an advantage because the elastic compression element will become more flexible at high temperatures and bend more when needed, and when the elastic compression element needs to remain rigid, it will be less flexible at lower temperatures. For example, when combined with the indicator protrusion as part of the over-compression prevention, the elastic compression element will be less flexible at lower temperatures. The elastic compression element can also help compensate for the thermal expansion state of the filter element during installation. That is, if the filter element is installed in cold weather, the elastic compression element will be harder and the indicator protrusion will pop out prematurely, so that when the system temperature cycles to high temperature, there will be no excessive load on the filter element. On the contrary, if the filter is installed in hot weather, the elastic compression element is flexible and will cause the indicator protrusion to pop out under a higher axial load, thus reducing the risk of gasket failure during the shrinkage of the filter at lower temperatures.

[0041] When used in a pulse filter, the resilient compression element can also act as a shock-absorbing system for vibrations and pulse energy caused by pulse events.

[0042] The bowl-shaped member preferably includes a ramp portion adjacent to the flange member, and the ramp portion is configured to be inserted into the front-end opening and fitted into the front-end opening of an air filter medium support cage disposed inside the hollow air filter medium pack, so as to facilitate the assembly of the air filter element.

[0043] The flange member may suitably include an air filter medium holding recess configured to receive the front end portion of the hollow air filter medium pack. The filter medium pack may preferably be fixed to the recess by means of a suitable adhesive.

[0044] The filter medium support cage may suitably be a cage assembly including two or more cage wall members extending from a first end to a second end in a length direction, and the cage assembly may have a lattice structure including column elements and beam elements, wherein the column elements provide the stability of the cage assembly in the length direction, and the beam elements connect the column elements and provide strength and stability in the circumferential direction. When the cage assembly is used for a pulse filter element mounted on a mounting frame, such as a tripod, the column elements of the wall members will also support the axial load applied to the filter cage assembly. The cage wall members may also include one or more blade-shaped column connection sections that are part of the lattice, so that the column connection plate elements and the beam elements can be arranged to connect the column elements at multiple points and thus be used to stabilize the cage assembly while still allowing air flow through. The cage wall members may also include one or more transverse support sections that are part of the lattice and extend in the circumferential direction of the cage, and the transverse support sections may be perpendicular to the length direction of the wall members or at an angle to the length direction of the wall members, and may include inclined transverse support elements extending between adjacent column elements, which can additionally reduce the risk of buckling of the cage during use.

[0045] As mentioned above, the present disclosure also relates to a pressure indicator gasket and a pressure indicator assembly including the pressure indicator gasket as described above, which can be used in combination with the front end plate as described above and in other cases where effective assembly of components without the risk of excessive tension is required. For example, the pressure indicator assembly can be used in combination with a conventional front end plate of the type commonly used in a hollow filter, with one end of the hollow filter being closed by the front end plate. Such filters are typically used in pulse filter applications.

[0046] The pressure indicator washer includes a main portion having a central opening configured to receive a connecting rod of a mounting bracket. The main portion is generally a disc-shaped member having a front side that will face outward when the pressure indicator washer is used for assembly or installation, and a rear side that will face rearward during assembly or installation. The indicator washer also includes at least one indicator protrusion disposed in the main portion. The indicator protrusion includes a contact portion that protrudes from the rear side of the main portion. The indicator protrusion is suitably configured to be pushed out from the front side of the main portion when the pressure applied to the rear side of the contact portion reaches a predetermined pressure limit.

[0047] The indicator protrusion preferably may include a weakened profile member intended to break when a predetermined pressure is applied to the rear side of the contact portion of the indicator protrusion. The weakened profile member is preferably a perforated line having an intermediate bridging member, i.e., a series of slots or holes having an intermediate bridging member that connects the top member of the indicator protrusion to the surrounding material of the main portion of the washer. The material thickness or width of the bridging member is selected such that the bridging member will break when a predetermined pressure is applied on the indicator protrusion, on the rear side of the indicator protrusion. Thus, the bridging member serves as a breakable link between the indicator protrusion and the main portion of the pressure indicator washer. Alternatively, the weakened profile may be a weakened line where the material connecting the main portion and the upper member of the indicator protrusion is thinner such that the material will break when a predetermined pressure is applied on the rear side of the indicator protrusion. The indicator protrusion is suitably connected to the pressure washer by a hinge portion such that the indicator protrusion remains in the washer even after it pops out.

[0048] The protruding contact portion of the indicator protrusion and the weakened profile member of the indicator protrusion are advantageously made of different materials. The material of the weakened profile member is selected to be brittle such that the weakened profile member will break instantaneously when a predetermined pressure is applied. A suitable material for the weakened profile member of the indicator protrusion can be glass fiber-filled nylon, and the entire washer except for the contact portion of the indicator protrusion can be made of this material. The contact portion can suitably be made of nylon.

[0049] The pressure indicator washer suitably includes a contact area on the front side of the main portion that surrounds the central opening and is configured to receive the force applied by a fastening element attached to the connecting rod during installation. The fastening element preferably can be a nut that is screwed onto the connecting rod during installation.

[0050] In some embodiments, the pressure indicator washer may include only one indicator protrusion. This may be suitable when the pressure indicator washer is used in combination with a compression element having a design such that it supports the rear side of the washer in a balanced manner.

[0051] In some other embodiments, the pressure indicator washer may include a plurality of pressure indicator protrusions. This may be suitable when the washer is to be used on a substantially flat surface where there are no protruding elements available to apply pressure to the rear side portion of the indicator protrusions. In such cases, the contact portion may need to extend rearwardly beyond the pressure indicator washer so that pressure can also be applied on the contact portion of the indicator protrusions through the substantially flat surface.

[0052] The pressure indicator washer may be included in a pressure indicator assembly as described above, which further includes a compression element having a central opening and at least one protruding element. The central opening of the compression element and the central opening of the pressure indicator washer are configured to receive a connecting rod. In this assembly, the pressure indicator washer is configured to be positioned on the compression element such that the central opening of the pressure indicator washer coincides with the central opening of the compression element during assembly. The protruding element points towards the rear side portion of the pressure indicator washer, and the indicator protrusions of the pressure indicator washer have positions aligned with the positions of at least one protruding element of the compression element. The compression element suitably includes a plurality of protruding elements distributed around the central opening. At least one of the protruding elements may suitably include a recess configured to receive a portion of the contact portion of the indicator protrusion disposed in the pressure indicator washer to facilitate proper alignment of the pressure indicator washer with the compression element. The compression element is suitably an elastic compression element and may be made of the materials described above.

[0053] The pressure indicator assembly may preferably include a base plate adapted to be positioned on the rear side portion of the compression element opposite to the pressure indicator washer. The base plate has a central opening for receiving the connecting rod of the mounting bracket and may preferably have a circumferential flange adapted to engage with the compression element during assembly. The pressure indicator washer may suitably include a circumferential flange adapted to engage with the compression element during assembly. In this way, the pressure indicator washer together with the compression element and the base plate can form a self - contained unit that can be used for any suitable application.

[0054] In addition, the base plate may include an engagement portion adapted to engage with an opening in the front end plate of the hollow air filter to securely hold the pressure indicator assembly in place during installation. If the base plate is not used, such an engagement portion may be provided on the rear side portion of the compression element or on the rear side portion of the pressure indicator washer.

[0055] The compression element may be provided as a separate component, sandwiched in the pressure indicator assembly, or may be an integral part of the pressure indicator washer or the base plate.

[0056] As mentioned above, the present disclosure also relates to a front end plate of an air filter, which is configured to enclose a front end portion of a hollow air filter medium pack. The front end plate includes a central member and a flange member positioned along a periphery of the central member. The central member includes a connection point located at a center of the central member and configured to connect to a front end portion of a mounting bracket in an air filter device, wherein the pressure indicator gasket as described above is disposed at the connection point. Advantageously, the pressure indicator gasket is included in the pressure indicator assembly as described above, and if desired, the compression element can be joined to the air filter front end plate by an adhesive or co-injection molding.

[0057] The present disclosure also relates to an air filter element, which includes the above-described air filter front end plate, a hollow air filter medium pack, and a rear end plate. The present disclosure also relates to an air filter device, which includes the air filter element, a mounting bracket, and an air filter base plate having an air flow opening. The filter element is fastened to the mounting bracket, and the rear end plate faces the base plate. The front end portion of the mounting bracket is connected to the air filter front end plate of the filter element at the connection point such that a connecting rod is inserted through a central opening of the pressure indicator gasket, and a fastening element is fastened relative to the connecting rod. The indicator protrusion is adapted to be pushed out from a front side portion of a main portion of the pressure indicator gasket when the pressure applied to a rear side portion of a contact portion of the gasket reaches a predetermined pressure limit. Two end-open second air filter elements may be disposed between the air filter element and the air filter base plate. The connecting rod is suitably part of the mounting bracket, and the mounting bracket is preferably a tripod. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The above and other objects, features, and advantages of the present disclosure will be more fully understood from the following illustrative and non-limiting detailed description of example embodiments of the present disclosure when considered in conjunction with the accompanying drawings.

[0059] Figure 1 A cross-sectional view of a front end plate according to the present disclosure is shown, and also shown are a connecting member 135 and a nut 19 belonging to the mounting bracket;

[0060] Figure 2a and Figure 2b shows Figure 1 a cross-sectional view of the front end plate and the connecting member in Figure 2a and an enlarged view of the indicator protrusion in an initial first position ( Figure 2b ) and a popped-up second position;

[0061] Figure 3Shows a cross-sectional perspective view of an air filter device, which includes two filter cartridges on top of each other, where the top cartridge includes a front end plate according to the present disclosure.

[0062] Figure 4 Shows a top view of a pressure indicator gasket according to the present disclosure;

[0063] Figure 5 Shows Figure 4 details of;

[0064] Figure 6 Shows Figure 4 a cross-sectional perspective view of the pressure indicator gasket of;

[0065] Figure 7 Shows a cross-sectional perspective view of the pressure indicator gasket, where the indicator protrusion has popped out;

[0066] Figure 8 Shows a cross-sectional perspective view of a pressure indicator assembly according to the present disclosure;

[0067] Figure 9 Shows a cross-sectional perspective view of the front end plate according to the present disclosure;

[0068] Figure 10 Shows a perspective view of the compression element as seen from the rear side;

[0069] Figure 11 Shows a perspective view of the compression element as seen from the front side. Detailed Description

[0070] The present disclosure will now be described with reference to the accompanying drawings, in which preferred exemplary embodiments of the present disclosure are shown. However, the present disclosure may be implemented in other forms and should not be construed as limited to the embodiments disclosed herein. The disclosed embodiments are provided to fully convey the scope of the present disclosure to those skilled in the art.

[0071] Figure 1 Shows a front end plate according to an exemplary embodiment of the present disclosure. Figure 3 Illustrates how the front end plate can be attached to a mounting bracket in an air filter device. The air filter front end plate 1 is configured to enclose the front end portion 102 of the hollow air filtration medium pack 101 ( Figure 3)。The front end plate includes a bowl-shaped member 2 and a flange member 3 positioned along the periphery 4 of the bowl-shaped member 2. The bowl-shaped member includes a connection point 5 located at the center of the bowl-shaped member and configured to connect to the front end portion 132 of the mounting bracket 131 in the air filter device 200. The bowl-shaped member 2 extends from the front end portion 21 to the rear end portion 22 of the air filter front end plate and is configured to be at least partially inserted into the front end opening 102 of the hollow air filter medium pack 101, and wherein the bowl-shaped member 2 has a reverse curved shape, having a first curved portion 7 positioned closer to the front end portion 21 and a second curved portion 8 positioned closer to the rear end portion 22, wherein the first curved portion 7 has a convex shape relative to the center line passing through the air filter front end plate, while the second curved portion 8 has a concave shape relative to the center line, whereby the connection point 5 is located in a position in front of the second curved portion 8. The second curved portion 8 of the bowl-shaped member 2 forms a recess 9 on the rear side portion 23 of the air filter front end plate, and the recess 9 is adapted to receive the connection member 135 attached to the mounting bracket 131( Figure 3 )。

[0072] The connection point 5 includes an opening 11 and a connection device located on the front side portion 24 of the bowl-shaped member 2. The connection device includes a pressure cover 13 and an elastic compression element 12 disposed between the bowl-shaped member 2 and the pressure cover 13. The elastic compression element 12 is an integral one-piece element, preferably an integral one-piece element made of an elastic polymer material, and is interlocked with the edge 14 of the opening 11 to be attached to the bowl-shaped member. The bowl-shaped member and the elastic compression element are preferably co-injection molded.

[0073] Two or more protruding portions 17 extend in the forward direction from the base portion 18 of the elastic compression element 12, and the elastic compression element 12 also has a central opening 15 for receiving a connection member in the form of a connecting rod 135. The pressure cover 13 also has a central opening 16 for receiving the connecting rod 135. The pressure cover 13 is provided with one or more indicator protrusions 26, and the indicator protrusions 26 are configured to be pushed in the forward direction by the compression element 12 when the pressure applied to the pressure cover 13 and the compression element 12 reaches a predetermined pressure limit. Figure 2a The indicator protrusion is shown in the initial position, and Figure 2b The subsequent pop-up position of the indicator protrusion is shown;

[0074] The bowl-shaped member 2 includes a ramp portion 10 adjacent to the flange member 3, and the ramp portion 10 is configured to be inserted into the front end opening 102 of the filter medium pack and fitted into the front end opening 104 of the air filter medium support cage 103 disposed inside the filter medium pack 101. The flange member 3 includes an air filter medium holding recess 25, and the air filter medium holding recess 25 is configured to receive the front end portion of the hollow air filter medium pack 101.

[0075] Figure 3 A cross-sectional perspective view of an air filter device including two filter cartridges 110 and 111 on top of each other is shown, and an example of how the filter cartridge 110 can be installed in the air filter device is illustrated. The air filter device is preferably a pulse filter device. A support cage is arranged inside the hollow filter medium pack 101, and the front end plate 23 closes the hollow air filter medium at the front end portion 104 of the support cage. A mounting bracket 131 in the form of a tripod is attached above the air passage opening 133 in the base plate 134. The two filter cartridges 110, 111 are placed on the tripod, with the rear filter cartridge 111 closest to the opening 133, and the rear end plate 113 of the rear filter cartridge 111 abuts against the surface of the base plate 134. The front filter cartridge 110 is positioned such that its rear end plate 105 contacts the front end plate 112 of the rear filter cartridge 111. A connecting member in the form of a connecting rod 135 at the front end portion 132 of the tripod is inserted through the front end plate of the front filter cartridge and fastened by, for example, a nut 19 (as Figure 1 shown). Other methods of installing the air filter cartridge can be envisioned. In Figure 3 , the illustrated front end plate has Figure 1 , Figure 2a and Figure 2b the configuration of the front end plate illustrated in

[0076] Figures 4 to 7 . However, except for the bowl-shaped shape of the front end plate, an air filter device including a substantially flat front end plate will include the same components.

[0076] Figures 4 to 7 An illustration of a pressure indicator gasket according to the present disclosure is shown. The pressure indicator gasket 13 includes a main portion 33 having a front side portion 31 and a rear side portion 3 and a central opening 45 configured to receive the connecting rod 135 of the mounting bracket (as illustrated in Figure 3 ). An indicator protrusion 26 is provided in the gasket, and the gasket includes a contact portion 41 protruding from the rear side portion of the main portion. The indicator protrusion 26 is configured to be pushed out from the front side portion of the main portion when the pressure applied to the rear side portion 34 of the contact portion 41 reaches a predetermined pressure limit, as illustrated in Figure 7 .

[0077] Figure 4 and Figure 5 show how the indicator protrusion 26 includes a weakened profile member 35 in the form of a perforated line having an intermediate bridging member 39. The indicator protrusion 26 is connected to the pressure gasket by a hinge portion 40. A contact area 38 is located on the front side portion 31 of the main portion and surrounds the central opening 45, as shown in Figure 6 . This contact area is configured to receive the force applied by the fastening element 19 attached to the connecting rod 135 during installation. Figure 3Illustrated is the fastening of the washer by means of the nut 19 screwed onto the connecting rod 135. Figure 6 in which the indicator protrusion is in its initial state, i.e., not yet popped out, and in Figure 7 in which, the indicator protrusion has popped out.

[0078] Figure 8 Illustrated is a pressure indicator assembly according to the present disclosure, and Figure 9 Illustrated is a front end plate including the pressure indicator assembly. The pressure indicator assembly includes Figures 4 to 7 the pressure indicator washer shown in and a compression element 12 having a central opening 46 and at least one protruding element 17. As Figure 8 and Figure 9 shown in, the pressure indicator washer 13 is positioned on the compression element 12 such that the central opening 45 of the pressure indicator washer 13 coincides with the central opening 46 of the compression element in the assembly. The central opening 46 of the compression element 12 and the central opening 45 of the pressure indicator washer 13 are configured to receive the connecting rod 135 as illustrated in Figure 3 . The protruding element 17 points to the rear side portion 32 of the pressure indicator washer 13, and the indicator protrusion 26 has a position aligned with the position of the protruding element 17 of the compression element 12.

[0079] As Figure 10 shown in, the pressure indicator assembly may include a base plate 42, which is adapted to be positioned on the rear side portion of the compression element 12 opposite to the pressure indicator washer. The base plate 42 has a central opening 47 and may further include a engaging portion 48, which is adapted to engage with an opening in the front end plate 50 of the hollow air filter ( Figure 8 and Figure 9 ) to firmly hold the pressure indicator assembly in place during installation. The base plate may further include a circumferential flange 43, which is adapted to engage with the compression element 32 during assembly, as Figure 8 shown in. Figure 8 and Figure 9 Also illustrated is how the pressure indicator washer 13 includes a circumferential flange 44 adapted to engage with the compression element 12 during assembly. As Figure 11 shown in, the compression element 12 includes a plurality of protruding elements 17 distributed around the central opening 46. The protruding element may include a recess 49, which is configured to receive a part of the contact portion of the indicator protrusion.

[0080] Those skilled in the art will recognize that the present disclosure is not limited to the above preferred embodiments. Those skilled in the art will also recognize that modifications and variations can be made within the scope of the appended claims. In addition, by studying the drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments when practicing the claimed disclosure.

Claims

1. An air filter front plate (1), the air filter front plate (1) being configured to enclose a front end portion (102) of a hollow air filter medium pack (101), the front plate including a bowl-shaped member (2) and a flange member (3) positioned along a periphery (4) of the bowl-shaped member (2), the bowl-shaped member including a connection point (5) located at a center of the bowl-shaped member and configured to be connected to a front end portion (132) of a mounting bracket (131) in an air filter device, characterized in that, The bowl-shaped member (2) extends from the front end portion (21) of the air filter front plate towards the rear end portion (22), and is configured to be at least partially inserted into the front end opening (102) of the hollow air filter medium pack (101), and wherein the bowl-shaped member (2) has an inflected shape, having a first curved portion (7) positioned closer to the front end portion (21) and a second curved portion (8) positioned closer to the rear end portion (22), wherein the first curved portion (7) has a convex shape with respect to the center line passing through the air filter front plate, while the second curved portion (8) has a concave shape with respect to the center line, whereby the connection point (5) is located in a position in front of the second curved portion (8).

2. The front end plate of the air filter according to claim 1, wherein, The second curved portion (8) of the bowl-shaped member (2) is configured to form a recess (9) on the rear side portion (23) of the air filter front plate, and the recess is adapted to receive a connection member (135) attached to the mounting bracket (131).

3. The front end plate of the air filter according to claim 1 or 2, wherein, The connection point (5) includes an opening (11), and a connection device is positioned on the front side portion (24) of the bowl-shaped member (2), and the connection device includes an elastic compression element (12) and a pressure cover (13), and the elastic compression element (12) is arranged between the bowl-shaped member (2) and the pressure cover (13).

4. The front end plate of the air filter according to claim 3, wherein, The elastic compression element (12) includes two or more protruding portions (17) extending in the forward direction from a base portion (18).

5. The front end plate of the air filter according to claim 3 or 4, wherein, The elastic compression element (12) has a central opening (15), and the central opening (15) is configured to receive a connection member (135) to be inserted through the opening (11) in the bowl-shaped member (2).

6. The front end plate of the air filter according to any one of claims 3 to 5, wherein The elastic compression element (12) is an integral one-piece element, preferably an integral one-piece element made of an elastic polymer material, and most preferably an integral one-piece element made of a thermoplastic elastomer material.

7. The front end plate of the air filter according to any one of claims 3 to 6, wherein, The elastic compression element (12) is configured to interlock with the edge (14) of the opening (11) to be attached to the bowl-shaped member, and is preferably obtained by co-injection molding.

8. The air filter front end plate according to any one of claims 3 to 7, wherein, The pressure cover (13) has a central opening (16), and the central opening (16) is configured to receive the connection member (135).

9. The air filter front panel according to any one of claims 3 to 8, wherein, The pressure cover (13) includes one or more indicator protrusions (26), and the one or more indicator protrusions (26) are configured to be pushed in the forward direction by the compression element (12) when the pressure applied to the pressure cover (13) and the compression element (12) reaches a predetermined pressure limit.

10. The air filter front end plate according to any one of claims 1 to 9, wherein, The bowl-shaped member (2) includes a ramp portion (10) adjacent to the flange member (3), and the ramp portion is configured to be inserted into the front end opening (102) and fitted into the front end opening (104) of an air filter medium support cage (103) arranged on the inner side portion of the hollow air filter medium pack (101).

11. The air filter front panel according to any one of claims 1 to 10, wherein, The flange member (3) includes an air filter medium holding recess (25) configured to receive the front end portion of the hollow air filter medium pack (101).

12. An air filter element (110), the air filter element (110) comprising an air filter front end plate (1), an air filtration medium support cage (103), a hollow air filtration medium pack (101) and a rear end plate (105) according to any one of claims 1 to 12, wherein, The air filter medium support cage (103) is disposed inside the hollow air filter medium pack (101), and the air filter front end plate (1) is inserted into the front end opening (104) of the air filter medium support cage (103) and the front end opening (102) of the air filter medium pack (101).

13. An air filter device (200), the air filter device (200) comprising an air filter element (110) according to claim 12, a mounting bracket (131), and an air filter base plate (134) having an air flow opening (133), wherein, The filter element is fastened to the mounting bracket, and the rear end plate (105) faces the base plate (134), and wherein the front end portion (132) of the mounting bracket is connected to the air filter front end plate (1) of the filter element (110) at the connection point (5).

14. The air filter device according to claim 13, wherein, A second filter element (111) having an open front end plate (112) is disposed between the air filter element (110) according to claim 13 and the base plate (134).

15. The air filter device according to claim 13 or 14, wherein, The mounting bracket (131) is a tripod.

16. A pressure indicator washer (13) comprising a main portion (33) having a central opening (45) configured to receive a connecting rod (135) of a mounting bracket, the main portion having a front side portion (31) and a rear side portion (32), the indicator washer further comprising at least one indicator protrusion (26) provided in the main portion, the indicator protrusion including a contact portion (41) protruding from the rear side portion of the main portion.

17. The pressure indicating washer according to claim 16, wherein, The indicator protrusion (26) is configured to be pushed out from the front side portion of the main portion when the pressure applied to the rear side portion (34) of the contact portion (41) reaches a predetermined pressure limit.

18. The pressure indicating washer according to claim 16 or 17, wherein, The indicator protrusion (26) includes a weakened profile member (35), which is preferably a perforated line or a weakened line having an intermediate bridging member (39).

19. The pressure indicating washer according to claim 18, wherein, The protrusion (26) is connected to the pressure washer by a hinge portion (40).

20. The pressure indicating washer according to any one of claims 16 to 19, wherein, The protruding contact portion (41) of the indicator protrusion and the weakened profile member (35) are made of different materials.

21. The pressure indicator washer according to any one of claims 16 to 20, further comprising a contact area (38) on the front side portion (31) of the main portion (33), the contact area (38) surrounding the central opening (45) and configured to receive the force applied by a fastening element (19) attached to the connecting rod (135) during installation, the fastening element (19) being preferably a nut screwed onto the connecting rod (135) during installation.

22. The pressure indicator washer according to any one of claims 16 to 21, including a plurality of pressure indicator protrusions (26).

23. A pressure indicator assembly (30), the pressure indicator assembly (30) comprising a pressure indicator gasket (13) according to any one of claims 16 to 22 and a compression element (12) having a central opening (46) and at least one projecting element (17), the central opening (46) of the compression element (12) and the central opening (45) of the pressure indicator gasket (13) being configured to receive a connecting rod (135), wherein, The pressure indicator washer (13) is configured to be positioned on the compression element (12) such that, upon assembly, the central opening (45) of the pressure indicator washer (13) coincides with the central opening (46) of the compression element, and the at least one protruding element (17) points towards the rear side portion (32) of the pressure indicator washer (13), and wherein the indicator protrusion (26) of the pressure indicator washer (13) has a position aligned with the position of the at least one protruding element (17) of the compression element (12).

24. The pressure indicator assembly according to claim 23, wherein, The compression element (12) is an elastic compression element.

25. The pressure indicator assembly according to claim 23 or 24, further comprising a base plate (42) adapted to be positioned on the rear side portion of the compression element (12) opposite the pressure indicator washer, the base plate (42) having a central opening (47) and preferably having a circumferential flange (43) adapted to engage the compression element (32) upon assembly.

26. The pressure indicator assembly according to any one of claims 23 to 25, wherein, The pressure indicator washer includes a circumferential flange (44) adapted to engage the compression element (12) upon assembly.

27. An air filter front panel (50), the air filter front panel (50) being configured to enclose a front end portion (102) of a hollow air filter media pack (101), the front panel including a central member (2) and a flange member (3) positioned along a periphery (4) of the central member (2), the central member including a connection point (5) that is located at the center of the central member and is configured to connect to a front end portion (132) of a mounting bracket (131) in an air filter device, wherein, The pressure indicator washer (13) according to any one of claims 16 to 22 is arranged at the connection point (5).

28. The air filter front plate (50) according to claim 27, wherein, The pressure indicator washer (13) is included in the pressure indicator assembly (30) according to any one of claims 23 to 26.

29. An air filter element (110), the air filter element (110) comprising the air filter front plate (50) according to claim 27 or 28, as well as a hollow air filter medium pack (101) and a rear end plate (105).

30. An air filter device (200), the air filter device (200) comprising an air filter element (110) according to claim 29, a mounting bracket (131), and an air filter base plate (134) having an air flow opening (133), wherein, The filter element is fastened to the mounting frame, and the rear end plate (105) points towards the base plate (134), and wherein the front end portion (132) of the mounting frame is connected to the air filter front plate (50) of the filter element (110) at the connection point (5) such that the connecting rod (135) is inserted through the central opening (45) of the pressure indicator washer (13), and the fastening element (19) is fastened relative to the connecting rod (135), wherein the indicator protrusion (26) is adapted to be pushed out from the front side portion (31) of the main portion (33) of the pressure indicator washer (26) when the pressure applied to the rear side portion (34) of the contact portion (41) of the washer reaches a predetermined pressure limit.

31. The air filter device according to claim 30, wherein, A second air filter element (111) is arranged between the air filter element (110) and the air filter base plate (134).

32. The air filter device according to claim 30 or 31, wherein, The connecting rod (135) is part of a mounting frame (131), and the mounting frame is preferably a tripod.

Images