Did You Know...
...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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| Number | Title | Issue Date |
| 7784489 | Check valve for a self-priming pump A check valve of the flapper type structured for use in a self-primer pump is structured for attachment to the pump casing in a manner that facilitates servicing of the check valve, and includes securement means that are positioned external to the casing and a flapp... | 08/31/2010 |
| 7249611 | Check valve A top entry check valve including a valve body with an access port. A compressible hanger body engages a portion of the valve body and is positioned in alignment with the access port of the valve body. A clapper is connected to the hanger body so that the clapper is... | 07/31/2007 |
| 7152622 | Check valve A top entry check valve including a valve body with an access port. A compressible hanger body engages a portion of the valve body and is positioned in alignment with the access port of the valve body. A clapper is connected to the hanger body so that the clapper is... | 12/26/2006 |
| 6694996 | Swing check backflow preventor having check valve with lever arm A swing check valve for controlling fluid flow, including a valve housing having a port for fluid flow therethrough. A valve assembly is disposed within the valve housing for controlling the fluid flow therethrough, and includes a valve seat communicating... | 02/24/2004 |
| 6679289 | Swing check valve The present invention relates to a light weight check valve for use in bulk material transfers that incorporates a smooth, generally spherical interior cavity to minimize flow inefficiencies. The check valve is made from two portions: a body portion and a... | 01/20/2004 |
| 6679290 | Swing check valve A check valve has a valve body with an annular seat surrounding the duct and a flap member pivotally mounted on the valve body so as to pivot about an axis transverse to the duct from an open position to a closed position pressing against the seat. The fl... | 01/20/2004 |
| 6328062 | Torsion spring connections for downhole flapper A torsion spring return system for a valve closure member, preferably for downhole use in an SSV, is described. The closure member or flapper uses torsion springs which can be wrapped circumferentially within the body of the downhole tool, generally follo... | 12/11/2001 |
| 6314993 | Swing check valve A check valve has a valve body with an annular seat surrounding the duct and a flap member pivotally mounted on the valve body so as to pivot about an axis transverse to the duct from an open position to a closed position pressing against the seat. The fl... | 11/13/2001 |
| 6050294 | Spring return check valve A resilient disc check valve with a spring return mechanism is provided. The spring return mechanism is contained entirely within the valve body. The spring return mechanism is in the form of a leaf spring or similar structure which engages a back side of... | 04/18/2000 |
| 5947152 | Check valve and backflow preventer A check valve or backflow preventer has a valve mechanism mounted to a valve cover for removal and replacement as a unit. The valve clapper is resiliently supported to accommodate variations in tolerance. The valve seat is removably secured within the val... | 09/07/1999 |
| 5794655 | Swing-type check valve assembly having an integrated valve seat and valve housing cover A swing-check valve for controlling fluid flow includes a valve housing and a valve assembly connected to a removable cover of the valve housing for rigid positioning of the valve assembly within the interior of the valve housing. Moreover, the valve asse... | 08/18/1998 |
| 5711341 | Swing-type check valve assembly retained within a valve housing by abutting engagement with a valve cover and a port of the valve housing A swing-check valve for controlling fluid flow includes a valve housing and a valve assembly that engages a removable cover of the valve housing for rigid positioning of the valve assembly within the interior of the valve housing when the cover is mounted... | 01/27/1998 |
| 5709240 | Check valve and backflow preventer A check valve or backflow preventer has a valve mechanism mounted to a valve cover for removal and replacement as a unit. The valve clapper is resiliently supported to accommodate variations in tolerance. The valve seat is removably secured within the val... | 01/20/1998 |
| 5236007 | Top-entry check valve having retainer ring A top-entry check valve having a seat, cage, disc and removable bonnet utilizes a retainer ring to prevent movement of the seat, cage and disc in the downstream direction. An annular shoulder in the valve body prevents movement of the seat, cage and disc ... | 08/17/1993 |
| 5156183 | Top-entry check valve having spring retainer A top-entry check valve has a valve chamber containing a seat, cage, disc and utilizes a spring retainer to prevent movement of the seat, cage and disc in the downstream direction. A removable bonnet covers an access opening the valve chamber. The seat an... | 10/20/1992 |
| 5131432 | Dishwasher with discharge pump and nonreturn valve A dishwasher with a wash tub (3) connected on the bottom to a collection well (4) into which extends the outlet duct (8) of a discharge pump (6) fitted with a nonreturn valve (11) accessible from the inside of the wash tub. The valve consists of a box-lik... | 07/21/1992 |
| 5056548 | Check valve assembly with removable seat A removable valve seat has a peripheral annular flange retained between an annular shoulder in a flow passage and a pair of retainer pins slidably received in bores defined in the valve body. The pins are not threadedly or otherwise engaged in the bores b... | 10/15/1991 |
| 4842014 | Check valve hanger mechanism The invention disclosed herein relates to a check valve clapper hanger mechanism from which a check valve clapper may be rotatably suspended in a check valve housing. The check valve clapper hanger mechanism is easily removable from the check valve housin... | 06/27/1989 |
| 4694853 | Wafer check valves A wafer check valve having an annular housing, closing flaps effective to close a passage through the housing and spring urged to a passage closing position, the flaps being mounted on one or more hinge pins, the or each hinge pin extending at each end in... | 09/22/1987 |
| 4552174 | Spring-loaded check valve A check valve particularly for use in large-volume applications includes a self-contained pressing unit which is mounted on a common pivot with the valve member in the outlet compartment of the valve housing and presses the valve member towards its closin... | 11/12/1985 |
| 4266569 | Check valve An improved check valve of rigid plastic tubing of inexpensive fabrication. The check valve is made of plastic tubing into which a chord-like slot is cut in one embodiment and into which is dropped in the process of manufacture a valve support arm to whic... | 05/12/1981 |
| 4259983 | Cleanout fitting with lockable and removable check valve A cleanout fitting has a tubular body adapted to be connected between a pair of conduits and having an upwardly open well defined between the upstream and downstream end of the body. This tubular body is formed internally with a downward upstream step and... | 04/07/1981 |
| 4252144 | Tilting disk check valve A tilting disc check valve wherein a valve module containing the tilting disc is positioned adjacent the inlet of the valve into a valve chamber by a cradle formed by a portion of the interior surface of the wall of the valve chamber and an arcuate ridge ... | 02/24/1981 |
| 4141381 | Swing check valve A swing check valve which includes a valve body having an inlet and outlet. A recess in the valve body designed to hold a seal ring and a check valve disc swingable between open and closed positions. The disc is supported by a high strength wire secured a... | 02/27/1979 |
| 4054153 | Check valve A check valve comprising a sectional valve body adapted to be interposed in a flow line, a valve seat provided in one body portion, a pivotal clapper member movable toward and away from said valve seat to provide alternate open and closed positions for th... | 10/18/1977 |
