Abstract: A filter element, at least consisting of a filter mat web (10), the free, mutually adjacent web ends (12) of which are joined along a joint (16), forming a hollow body, is characterized in that the joint (16) is made of at least one connecting part (18), which is provided with groove-shaped receiving channels (20, 22), each of which is used to receive one web end (12) of the filter mat (10).

Abstract: A method for producing a filter element for filtering fluids, such as hydraulic fluids, lubricants or fuels, includes the following steps: a) providing at least one section of a filter mat web (14) made of one or more layers of at least one filter medium; b) connecting the ends of the at least one section to form an annular body (12) and placing that annular body onto a support pipe (16); c) wrapping at least one cutout of a film web (8) around the outside of the annular body (12) located on the support pipe (16) and d) placing end areas (24) of the at least one cutout of the film web (8) one on top of the other and connecting the overlapping end areas (24).

Abstract: A filter element (20) includes individual components (2, 4, 8), such as a filter medium (8) as one component and further filter element components (2, 4), of which at least one component (4) is made of a material that is at least partially transparent to laser light and at least one further component (2), in the manner of a barrier layer, is made of a material that is at least partially opaque to laser light to perform a transmission welding method by laser light for connecting associable components to each other. At least some of the components of the filter element that are exposed to the laser light during the transmission welding method are at least partially electrically conductive.

Abstract: A method for forming a filter mat (1) suitable for filter fluids includes forming at least one web section (39) of a mat web (9) and at least one welding line (13, 15, 41) that seals the layers of at least one web section (39) of the mat web (9) to each other. Subsequently, at least one cut (19, 37) is carried out along the at least one welding line (13, 15, 41) such that the at least one web section (39) is cut forming at least one sealed edge region (43).

Abstract: The invention relates to a filter element (20), comprising individual components (2, 4, 8), such as a filter medium (8) as one component and further filter element components (2, 4), of which at least one component (4) is made of a material that is at least partially transparent to laser light and at least one further component (2), in the manner of a barrier layer, is made of a material that is at least partially opaque to laser light in order to perform a transmission welding method by means of laser light for the purpose of connecting associable filter elements to each other, wherein said method is characterized in that at least some of the components of the filter element that are exposed to the laser light during the transmission welding method are at least partially electrically conductive.

Abstract: The invention relates to a method for producing a filter element for filtering fluids, such as hydraulic fluids, lubricants, or fuels, comprising the following steps: a) providing at least one section of a filter mat web (14) made of one or more layers of at least one filter medium; b) connecting the ends of the at least one section in order to form an annular body (12) and placing said annular body onto a support pipe (16); wherein said method is characterized by: c) wrapping at least one cutout of a film web (8) around the outside of the annular body (12) located on the support pipe (16) and d) placing end areas (24) of the at least one cutout of the film web (8) one on top of the other and connecting the overlapping end areas (24).

Abstract: The invention relates to a method for forming a filter mat (1) suitable for filtering fluids, comprising at least one web section (39) of a mat web (9), at least one welding line (13, 15, 41) that seals the layers of at least one web section (39) of the mat web (9) to each other being formed. The invention is characterized in that subsequently at least one cut (19, 37) is carried out along the at least one welding line (13, 15, 41) such that the at least one web section (39) is cut forming at least one sealed edge region (43).

Abstract: 1. A method for the production of a filter element. 2. A method for the production of a filter element (1) comprising the steps: a) Providing a filter medium (3) surrounding an inner filter cavity (7) and comprising a heat-sealable material; b) Providing at least one end cap (9, 13) made of thermoplastic, laser-permeable material, forming a covering of the filter cavity (7) on at least one end; c) Forming a laser-impermeable barrier layer (31) between the end cap (9, 13) and the adjacent end of the filter medium (3) and d) Welding the end cap (9, 13) and filter medium (3) by irradiating laser-permeable material adjacent to the barrier layer (31) with laser energy such that, by heating the region adjacent to the barrier layer (31), a welding volume is provided as a joining element for the welded joint created by laser-transmission welding.

Abstract: A filter element includes a filter cylinder whose outer side rests against a fluid-permeable supporting tube (15). The inside (3) of the filter cylinder can be flown through by the fluid to be filtered. The filter cylinder is formed by a filter mat web. The filter mat web has a series of folds (9) that rest against one another at least in areas. Both ends of the filter mat web are joined to one another at a junction (5) to form an annular body (1). The filter element includes a device that acts upon the junction (5) to prevent, in the area of the junction (5), a bulging of the folds (9) caused by the flow of the fluid.

Abstract: A process for production of a filter element includes forming a cylinder by bending a flexible filter mat having a series of folds adjacent to one another at least in individual end areas on longitudinal end edges thereof such that the end areas overlap with end edges being aligned along a length of the cylinder, joining the end areas on an exterior of the cylinder along a junction seam, and reversing the cylinder inside out such that an annular filter element is formed with the junction seam on an interior thereof.

Abstract: A method produces a connection interface in a tubular filter element for filtering liquids, including a filter mat (10). The opposite ends (14) of the filter mat are interconnected in a connection position by a planar weld seam (28) provided with an embossed strip in the region of the free ends (14) of the filter mat. A region is provided between the embossed weld seam (30) and the beginning of the transition towards the tubular filter mats, in which a smooth weld seam (32) is applied without embossing in a flat strip along the ends (14) of the filter mat. This arrangement enables the ends of the filter mat to be welded together in a strong and long-lasting manner. The embossed weld seam is simultaneously unloaded of any stress by the smooth weld seam.

Abstract: The invention relates to a filter element comprising a filter cylinder whose outer side rests against a fluid-permeable supporting tube (15). The inside (3) of the filter cylinder can be flown through by the fluid to be filtered, and the filter cylinder is formed by a filter mat web. The filter mat web has a series of folds (9) that rest against one another at least in areas. Both ends of the filter mat web are joined to one another at a junction (5) in order to form an annolar body (1). The inventive filter element comprises a device that acts upon the junction (5) in order to prevent, in the area of the junction (5), a bulging of the folds (9) that is caused by the flow of the fluid.

Abstract: A tubular filter element and a device for producing the same for filtering fluids includes a filter mate. The facing ends of the filter mat are fixed in position by a connecting device which at least partially overlaps the filter mat.

Abstract: A method of assembling a filter element includes the initial step of forming a plastic filter casing with openings from a flat blank with opposite ends thereof bent towards one another and joining these opposite ends together by a sealing seam. Also, a resilient mat filter is folded into a cylindrical shape and pushed open on a fluid-permeable supporting pipe to surround and engage the surrounding pipe. The cylindrical shape of the mat filter has an exterior diameter prior to introduction into the casing that is larger than an interior diameter of the filter casing along the entire axial length of the mat filter. The mat folder is folded into a conical shape to facilitate its introduction thereof into the filter casing. After the axial end is formed, the mat filter and supporting pipe are introduced into the filter casing to define a filter chamber. Finally, two end caps are joined to the filter casing.

Abstract: The invention relates to a method for producing a connection interface in a tubular filter element for filtering liquids, comprising a filter mat (10), the opposite ends (14) of said filter mat being interconnected in a connection position by means of a plane weld seam (28) which is provided with an impressed strip in the region of the free ends (14) of the filter mat. A region is provided between the impressed weld seam (30) formed in such a way and the beginning of the transition towards the tubular filter mats, in which a smooth weld seam (32) is applied without impression in a flat strip along the ends (14) of the filter mat. This enables the ends of the filter mat to be welded together in a strong and long-lasting manner, the impressed weld seam being simultaneously unloaded of any stress by means of the smooth weld seam. The invention also relates to a device for carrying out the method.

Abstract: A filter with a multi-piece filter body has a filter head connected to a filter pot and has at least one filter element. The filter element has a support tube surrounded by a filter mat. The filter mat free ends have element mountings. One of the element mounting is rigidly connected to the support tube and can be placed in contact with the filter head. An intermediate member is arranged, at least at that end of the filter element mounting connected to the filter head, between that element mounting and that end of the filter mat, and can be removed along with the filter mat from the support tube which remains connected to the filter head.

Abstract: A filter device has a bypass valve which releases a fluid-conveying path to an outlet when a filter element becomes clogged. The bypass valve includes a closure part on which at least one closure spring acts. To adjust the spring pretension and the opening force for the closure part, an adjusting device is provided for adjusting the opening force of the closure spring. The filter device can be economically adapted without any structural modifications to very different applications in a predetermined pressure range.