Did You Know...
...that the x-ray was discovered purely by accident? When German physicist Wilhelm Konrad von Roentgen was experimenting with cathode rays in 1895, he put an activated Crookes tube in a book and went out to lunch. When he returned, he discovered that a key that had also been placed in the book showed up as an image on the developed film!
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| Number | Title | Issue Date |
| 7980836 | Modular multi-rotor compressor and method of manufacture A multi-rotor compressor and method of manufacturing is provided. The compressor includes a housing with a plurality of identical planet rotors. The planet rotors are equally spaced apart at a fixed distance from a centerline. A single sun rotor is provided that is ... | 07/19/2011 |
| 7452194 | Screw pump A pump including at least three rotors each being provided with a generally helical screw thread, the rotors being mounted for rotation in a housing such that the screw threads of the rotors mesh and rotation of one rotor causes rotation of the other rotor, wherein ... | 11/18/2008 |
| 7234925 | Screw pump A pump including a power rotor and an idler rotor, the rotors each being provided with a generally helical screw thread and being mounted for rotation in a housing such that the screw threads of the rotors mesh and rotation of one rotor causes rotation of the other ... | 06/26/2007 |
| 7232297 | Screw pump A pump including at least three rotors each being provided with a generally helical screw thread, the rotors being mounted for rotation in a housing such that the screw threads of the rotors mesh and rotation of one rotor causes rotation of the other rotor, wherein ... | 06/19/2007 |
| 7178352 | Compressor A compressor has at least three-rotors. A first compression path between first inlet and outlet ports is associated with interaction of the first and second rotors. A second compression path between second inlet and outlet ports is associated with interaction of the... | 02/20/2007 |
| 7121814 | Compressor sound suppression A compressor includes a housing and one or more working elements. A muffler is located downstream of the discharge plenum. A centerbody is located in the discharge plenum upstream of the muffler spanning a major portion of a length between a bearing case and the muf... | 10/17/2006 |
| 6976833 | Compressor discharge chamber with baffle plate A screw compressor is provided with a discharge chamber that receives alternating flows of compressed fluid from two compression chambers located on opposed sides of the screw compressor. The discharge chamber is provided with a central baffle plate separating the t... | 12/20/2005 |
| 6964559 | Two shaft vacuum pump with cantilevered rotors A vacuum pump (1) comprising a pump chamber casing (5) accommodating two co-operating rotors (2, 3) which are respectively arranged on a shaft (8, 9). A bearing/gear chamber (6) is disposed adjacent to the pump chamber casing (5... | 11/15/2005 |
| 6913452 | Offset thread screw rotor device A screw rotor device has a housing with an inlet port and an outlet port, a male rotor, and a female rotor. The male rotor has a pair of helical threads with a phase-offset aspect, and the female rotor has a corresponding pair of helical grooves. The female rotor co... | 07/05/2005 |
| 6821098 | Screw compressor having compression pockets closed for unequal durations A compressor has male and female rotors with enmeshed screw-type body portions. A housing cooperates with the rotors to define inlet and outlet chambers for pumping of fluid from/to when the male rotor in a first direction and the female rotor rotates in an opposite... | 11/23/2004 |
| 6739851 | Coated end wall and method of manufacture A compressor has a housing assembly and at least one rotor held by the housing assembly for rotation about a rotor axis. The rotor has a first face and a first housing element has a second face in facing spaced-apart relation to the first face of the rotor. The hous... | 05/25/2004 |
| 6719548 | Twin screw rotor device A screw rotor device has a housing with an inlet port and an outlet port and at least one pair of rotors. The rotors each have an identical number of threads (N), a buttress thread profile with a diagonal line, and a length that is either approximately equal to or l... | 04/13/2004 |
| 6638042 | Asymmetric porting for multi-rotor screw compressor A screw compressor includes a compressor housing defining parallel rotor housing sections, each rotor housing section containing a rotor, and adjacent rotors defining compressor pairs, the housing further including a suction port and a discharge port for ... | 10/28/2003 |
| 6623262 | Method of reducing system pressure pulsation for positive displacement pumps An improved method and apparatus for reducing pressure pulsation when pumping fluids having highly entrained gas therein. The pump has a drive screw and a pair of idler screws. The screws are placed in a screw channel between a suction end and a discharge... | 09/23/2003 |
| 6599112 | Offset thread screw rotor device A screw rotor device has a housing with an inlet port and an outlet port, a male rotor, and a female rotor. The male rotor has a pair of helical threads with a phase-offset aspect, and the female rotor has a corresponding pair of helical grooves. The fema... | 07/29/2003 |
| 6488480 | Housing for screw compressor A housing for a screw compressor, includes a single-piece casting defining a motor housing section and a rotor housing section and has an inlet for compressor medium, an outlet end and a bridge member disposed between the motor housing section and the rot... | 12/03/2002 |
| 6422846 | Low pressure unloader mechanism Two slide valves are located in the discharge end bearing case of a multi-rotor screw machine and independently coact with the sun rotor of the multi-rotor screw machine for controlling capacity and Vi. Movement of the slide valves is in a plan... | 07/23/2002 |
| 6217304 | Multi-rotor helical-screw compressor A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The male rotor is driven by a motor, in other words the male rotor is the drive rotor. The male rotor ha... | 04/17/2001 |
| 6093007 | Multi-rotor helical-screw compressor with thrust balance device A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The compressor includes a housing and a thrust balance configuration. The thrust balance configuration i... | 07/25/2000 |
| 5934891 | Constant leakage flow, pulsation free screw pump The screw pump (1) has a driving screw (6) and at least one side screw (7), which are placed in a screw channel (5) in the pump body (2), between a suction space (3) and a pressure space (4). At least one of the clearances between the surfaces of the driv... | 08/10/1999 |
| 5807091 | Multi-rotor helical-screw compressor A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The male rotor is driven by a motor, in other words the male rotor is the drive rotor. The male rotor ha... | 09/15/1998 |
| 5642992 | Multi-rotor helical screw compressor A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The male rotor is driven by a motor, in other words the male rotor is the drive rotor. The male rotor ha... | 07/01/1997 |
| 5601414 | Interstage liquid/gas phase detector A positive displacement rotary axial screw pump which comprises a series of sealed closures formed by meshing of the rotors for building the internal pressure gradient of the pump from the pump inlet to its outlet. A programmable logic circuit is provided... | 02/11/1997 |
| 5123821 | Screw spindle pump with a reduced pulsation effect In a displacement pump having at least one screw spindle which is mounted in an opening in a housing surrounding same between a suction chamber and a pressure chamber, the profile termination of the spindle, at the pressure end, is turned off in a conical... | 06/23/1992 |
| 5051077 | Screw compressor The present invention is drawn to a screw compressor having a wide operating range with respect to flow rate and pressure ratio, wherein a discharge opening portion of a casing is provided with a generally tapered notch portion so that compressed gas is g... | 09/24/1991 |
| 4877385 | Positive displacement rotary mechanism A positive displacement rotary mechanism has four identical rotary helical intermeshing lobes that cooperate with a stationary cylindrical member extending centrally thereof to define repetitive working space internal of the lobes having boundaries along ... | 10/31/1989 |
| 4860705 | Positive displacement rotary mechanism A positive displacement rotary mechanism has three and alternatively four identical rotary helical intermeshing lobes of continuously varying pitch that cooperate with a stationary cylindrical member extending centrally thereof to define a repetitive work... | 08/29/1989 |
| 4841930 | Positive displacement rotary mechanism A positive displacement rotary mechanism has three identical rotary helical intermeshing lobes that cooperate with a stationary cylindrical member extending centrally thereof to define a repetitive working space internal of the lobes having boundaries alo... | 06/27/1989 |
| 4782802 | Positive displacement rotary mechanism A positive displacement rotary mechanism has three and alternatively four identical rotary helical intermeshing lobes that cooperate with a stationary cylindrical member extending centrally thereof to define a repetitive working space internal of the lobe... | 11/08/1988 |
| 4776779 | Fluid motor or pump A rotodynamic fluid machine comprising a plurality of separate coaxial cylindrical chambers in each of which a drive rotor is positioned. The drive rotors mesh with corresponding sealing rotors and have blades that are curved in such a manner so that if t... | 10/11/1988 |
| 4773837 | Screw pump A screw pump including a screw assembly in a sleeve, the assembly comprising a drive screw having protruding threaded sides, and multiple driven screws having concave threaded sides which are closely meshed with the drive screw, thus forming a series of s... | 09/27/1988 |
| 4623305 | Device for pumping oil A device preferably utilized for pumping oil or other fluid from a drill hole in the ground, said device including a pump lowered into the hole and coupled to a drive motor situated under it. The pump comprises a hydraulic screw pump including a housing i... | 11/18/1986 |
| 4580953 | Screw pump including a fluid bypass regulating device A screw pump of the kind including a screw array consisting of a central screw (1) with convex flanks and one or more side screws (2) with concave flanks, the threads being formed such that coacting screws seal against each other with the screw array bein... | 04/08/1986 |
| 4547135 | Motor-pump unit A motor-pump unit consists of a screw shaft pump and a slot-barrel motor located on the pressure side of the pump. The motor-pump unit is provided with a rigid, preferably one-piece, shaft by which the motor drives the pump. The motor is located on the pr... | 10/15/1985 |
| 4302165 | Interengaging screw machine with radial inlet and/or outlet bore The invention relates to hydraulic screw machines of the type having a screw array in a sealingly surrounding housing. The object of the invention is to reduce the length of the machine with unchanged number of seals in the screw array. This is achieved b... | 11/24/1981 |
| 4242067 | Hydraulic screw machine with balance plunger A hydraulic screw machine comprises a driving screw and at least one impeller screw with a balance plunger at its end. The thread of the impeller screw is complete with full depth all the way to the balance plunger. The length of the plunger is less than ... | 12/30/1980 |
| 4028025 | Screw pump A screw pump having a unit which includes a drive screw and at least one impeller screw that meshes therewith, arranged within a casing that sealingly encloses the screws, each impeller screw on the pressure side being provided with a pin mounted in a sle... | 06/07/1977 |
| 4018549 | Screw pump A screw pump includes a screw unit having a drive screw and two impeller screws arranged symmetrically around the drive screw. The screws are enclosed in a housing having mutually intersecting passages for accommodating the screws, and the unit is constru... | 04/19/1977 |
| 3966371 | Rotary, positive displacement progressing cavity device A positive displacement, progressing cavity device with interengaging axially twisted rotors that define sealed cavities or chambers which develop at the inlet of the device and progress axially to the outlet of the device in response to synchronized roto... | 06/29/1976 |
