What is claimed is:
1. A liquid filter having a housing structure with an inlet and an outlet for the liquid to be filtered, in which a cylindrical filter insert with axial end plates is installed, and which has a bypass valve in the area of one of the end plates, wherein
the bypass valve comprises a valve body which is movably mounted in the filter insert and which in a closed state contacts a valve seat integrated in an end plate of the filter insert, and
a support member is mounted on the housing, said support member supporting a spring that is compressed against the valve body of the installed filter insert to urge the valve body against the valve seat.
2. A liquid filter according to claim 1, wherein the valve body is mounted so that it can move axially in the end plate of the cylindrical filter insert and wherein the bypass valve includes an axial stop which limits movement of the valve body away from the valve seat.
3. A liquid filter according to claim 2, wherein said axial stop is comprised of resilient tabs.
4. A liquid filter according to claim 1, wherein the valve body is comprised at least partially of an elastomer.
5. A liquid filter according to claim 1, wherein an intermediate piece is provided between the spring and the valve body to transmit force between the spring and valve body.
6. A liquid filter according to claim 1, wherein the support member is arranged in a cylindrical inner chamber of the filter insert such that a filter medium of the filter insert is supported on the support member.
7. A liquid filter according to claim 1, wherein the end plate with said valve seat is provided with a passage which connects to the outlet for the filtered liquid, and the bypass valve is mounted in said end plate parallel to said passage.
8. A liquid filter according to claim 7, wherein the valve body and the end plate with said valve seat surround said passage which connects to the outlet for the filtered liquid such that the bypass valve annularly surrounds said passage.
9. A liquid filter according to claim 1, wherein the housing structure is designed as a replacement filter.
10. A liquid filter according to claim 1, wherein said filter is an oil filter for an internal combustion engine.
11. A cylindrical filter insert with axial end plates and a bypass valve in the area of one of the end plates, wherein
the bypass valve comprises a valve body which is movably mounted in the filter insert and which in a closed state contacts a valve seat integrated in said one end plate of the filter insert, and
said filter insert being installable in a filter housing such that a spring mounted on the housing is compressed against the valve body to urge the valve body against the valve seat.
12. A filter insert according to claim 11, wherein the valve body is mounted so that it can move axially in said one end plate and wherein the bypass valve includes an axial stop which limits movement of the valve body away from the valve seat.
13. A filter insert according to claim 12, wherein said axial stop is comprised of resilient tabs.
14. A filter insert according to claim 11, wherein the valve body is comprised at least partially of an elastomer.
15. A liquid filter according to claim 11, wherein an intermediate piece is provided between the spring and the valve body to transmit force between the spring and valve body.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of creating a printed interactive document using a printer connected to a computer, said method comprising the steps of:
(a) receiving a print request for the interactive document at the computer, said print request being based on a document stored in the computer, said document including human-readable graphic content;
(b) requesting and retrieving a unique document identity in response to the print request;
(c) indexing the document with the unique document identity and archiving the indexed document in a database;
(d) sending the unique document identity and the graphic content of the document to the printer; and
(e) printing the graphic content onto a substrate and at the same time printing coded data coincident with the graphic content onto the substrate so as to create the printed interactive document, said coded data identifying the unique document identity and a plurality of locations on the substrate,
wherein the printed interactive document is interactive by virtue of the coded data functioning in cooperation with the graphic content to provide user interactivity with the graphic content.
2. The method of claim 1, wherein the coded data comprises a plurality of tags, each tag encoding its position on the substrate.
3. The method of claim 2, wherein each tag identifies the unique identity of the document.
4. The method of claim 2, further comprising the step of:
interacting with graphic content of the printed interactive document using an optically imaging pen having an image sensor;
imaging at least one tag using the image sensor;
decoding the tag to provide the position of the pen relative to the substrate and the unique identity of the document;
sending interaction data to a computer system, said interaction data identifying the position of the pen relative to the substrate and the unique identity of the document, thereby causing the computer system to initiate an action indicated by the interaction by looking up the indexed document.
5. The method of claim 4, wherein the step of interacting with the graphic content of the printed interactive document indicates a request for a copy of the document.
6. The method of claim 4, wherein the step of interacting with the graphic content of the printed interactive document indicates handwritten input on the document.
7. The method of claim 6, wherein the handwritten input causes the computer system to update a page instance corresponding to the printed interactive document.
8. The method of claim 2, wherein the printer generates the coded data from the unique document identity using a tag encoder.
9. The method of claim 1, wherein the coded data is printed using IR-absorbing ink.