Abstract: A hand-operated electric tool, especially a jigsaw, has a motor unit provided in the tool housing. The motor unit contains in a motor housing the stator and the rotor. One end of the rotor shaft projects from the motor housing and is mounted in two bearings fixed in the motor housing. A countershaft forms an extension of the rotor shaft and carries a toothed arrangement. The countershaft is coupled to the rotor shaft and is rotatably mounted in a bearing. The rotor shaft and countershaft engage axially with radial play and are coupled non-rotatably by co-operating radial projections and recesses receiving the projections. In the region of the overlapping portions of rotor shaft and countershaft, one of the shafts has an annular portion extending at least over a part of the circumference. The annular portion is substantially in line contact with an adjacent circumferential surface of the other shaft. The line contact permits misalignment of the rotor shaft and countershaft but reduces noise.

Abstract: An air directing baffle for a random orbit sander. The baffle includes a main body portion forming an annular opening, a pair of neck portions extending approximately circumferentially opposite from one another, and a pair of recessed portions formed in each of the neck portions. The neck portions extend into airflow registration with a plurality of exhaust slots formed in a shroud rotatably disposed at a lower portion of a housing of the sander. The annular opening is adapted to fit over a boss portion protruding from a lower face surface of the housing of the sander to thus permit the baffle to be rotated freely relative to the housing. The recessed portions in each of the neck portions of the baffle inwardly engage with a pair of inwardly protruding shoulder portions formed in an interior area of the shroud.

Abstract: A random orbit sander having a braking member for frictionally controlling the speed of a platen of the sander when the sander is removed from a workpiece during operation. The braking member includes a base portion, an outwardly flaring, relatively thin wall portion and an enlarged outermost edge portion adapted to frictionally engage an upper surface of the platen. The braking member is secured to the bottom of the shroud of the housing via a groove formed in its base portion. The braking member exerts a relatively constant spring force against the upper surface of the platen which limits the rotational speed of the platen to approximately 1200 rpm when the platen is lifted off of a work surface, without significantly degrading the performance of the sander under load.

Abstract: The present invention provides a method of preventing gas migration during primary well cementing. The method basically comprises the steps of displacing a cement slurry into the annulus between a string of pipe to be cemented in a well bore and the walls of the well bore, determining the initial surface pressure in the pipe after the cement slurry is placed in the annulus, displacing additional cement slurry into the annulus as is necessary to make up for losses in the surface pressure due to cement slurry gel strength development and volume reduction whereby the surface pressure is maintained substantially equal to the initial surface pressure until the cement slurry develops a predetermined gel strength sufficient by itself to prevent gas migration, and then allowing the cement slurry to set into a hard impermeable mass in the annulus.

Abstract: Methods and apparatus for cementing a pipe in a well bore penetrating one or more subterranean gas-containing formations without incurring substantial gas inflow are provided. The methods basically comprise the steps of placing a hydraulic cement slurry in the annulus between the pipe and the well bore, and moving the pipe during the transition period of the slurry. The moving of the pipe maintains the hydrostatic pressure exerted by the slurry on the gas-containing formations and prevents gas flow into the slurry and the well bore. The movement of the pipe is stopped when the slurry develops sufficient gel strength to substantially block gas flow through the well bore.

Abstract: The invention is directed to a method for rapidly forming a dense pattern of via holes in multilayer electronic circuits in which via holes in the dielectric layers are formed by drilling with an excimer laser under controlled operating conditions.

Abstract: An accessory for inflating and deflating inflatable articles comprises a conduit 13, an intake 17, an outtake 19 and an injector 35. In use, conduit 13 functions as a venturi tube for rapid inflation and deflation of inflatable articles, preferably, articles having a large, low pressure air volume. For inflation, outtake 19 is connected to the inflatable article. For deflation, intake 17 is connected to the inflated article. For inflation and deflation, a source of pressurized air, preferably, an electric air compressor is connected to injector 35.

Abstract: Set delayed cement compositions capable of being retained in pumpable fluid states for long time periods and then activated to set into hard masses and methods of using such compositions for cementing zones at remote locations are provided. The compositions are comprised of hydraulic cement, water, one or more hydratable gel forming materials and one or more methylenephosphonic acid derivative set delaying agents.

Abstract: A positive stirring consistometer cup includes a pair of wall blade members having radially inwardly extending blades which cooperate with radially outwardly extending blades of a paddle to uniformly apply shear throughout a substance to be tested. A split sleeve assembly eliminates an outer dead space, and an enlarged spacer member mounted on the shaft of the paddle eliminates an inner dead space, thereby enhancing the uniformity of the shear throughout the substance. A centralizing assembly centers the stationary paddle while causing a minimum of friction and wear to occur on the shaft of the paddle. In a method of using the positive stirring consistometer cup, the blades of the wall blade members and of the paddle stop in substantially aligned, coplanar relationship to facilitate cleaning of the elements after a test is concluded.

Abstract: An environmentally compatible high density drilling, blow-out control fluid, or cement composition is provided wherein densities between twenty-four (24) and forty (40) pounds per gallon can be achieved. Such preferred fluid is aqueous based, uses a non-toxic gelling agent such as fine iron oxide powder, a coarser first weighting material such as fine iron powder, and a second still coarser weighting material such as iron shot, steel shot or mixtures thereof.

Abstract: An essentially dry gas generation retarded aluminum powder for oil field cements is provided. The retarded aluminum powder is formed by dissolving an effective amount of an aluminum reaction rate retarder in an organic solvent, the retarder being selected from fatty acid esters of sorbitan, glycerol and pentaerythritol. Aluminum powder is mixed with the retarder-solvent solution whereby the aluminum powder is wetted with the solution followed by drying the aluminum powder by vacuum evaporating and removing the organic solvent therefrom. Methods of forming gas generation retarded oil field cements and using such cements are also provided.

Abstract: An environmentally compatible high density drilling or blow-out control fluid is provided wherein densities between twenty-four (24) and forty (40) pounds per gallon can be achieved. Such preferred fluid is aqueous based, uses a non-toxic gelling agent such as fine iron oxide powder, a coarser first weighting material such as fine iron powder, and a second still coarser weighting material such as iron shot, steel shot or mixtures thereof.

Abstract: A composition for a method of cementing subterranean formations. The cementing composition comprises hydraulic cement, a nitrogen gas generating material, an oxidizing agent, and a reaction rate control material. The concentration of the nitrogen gas generating material is correlated with the pressure and temperature of the cement zone to be cemented so that the flow of gas from the formation into the borehole is suppressed or controlled.

Abstract: A fluid loss test can be performed using a housing having a substantially cylindrical core disposed therein and having a cage paddle structure disposed therein substantially coaxially around the core thereby permitting continuous agitation and even fluid shear rates to be maintained during test periods. The core has an axial opening defined therein through which lost fluid permeating the core can be collected. The core is secured in the housing so that reverse flow permeability tests can be conducted thereon. Although secured in the housing during tests, the core is removable therefrom so that filter cakes applied to the core can be analyzed. The housing is maintained within a system which permits successive fluids to be introduced into the housing while maintaining substantially constant system pressure. Additionally, measured volumes of fluid can be introduced into the housing.

Abstract: A process and method for cementing adjacent to a subterranean gas containing zone. The cementing compositions comprise a hydraulic cement, aluminum powder ot generate hydrogen gas, and an inhibitor which retards the generation of hydrogen gas produced by the aluminum powder.

Abstract: A process for cementing adjacent a subterranean gas-containing zone, in which process a cement slurry containing a stabilized, dispersed gas is placed adjacent the zone. Sufficient gas is present in the cement slurry or is capable of being generated within the slurry to prevent the connate formation gas under pressure from passing into or around the cement prior to the time the cement has set up.

Abstract: A process for cementing adjacent a subterranean gas-containing zone, in which process a cement slurry containing a stabilized, dispersed gas is placed adjacent the zone. Sufficient gas is present in the cement slurry or is capable of being generated within the slurry to prevent the connate formation gas under pressure from passing into or around the cement prior to the time the cement has set up.

Abstract: Methods and apparatus for the nondestructive testing of cement slurry samples as a function of time are disclosed. A sample placed in a temperature and pressure controlled autoclave is coupled to transducer means under computer control. Ultrasonic energy is propagated through the sample and the transit time is measured. A predetermined relationship relating transit time to compressive strength is employed and enables the determination of compressive strength. The measurements are repetitively performed on up to eight samples simultaneously and the time history of the development of compressive strength is recorded.

Abstract: The present invention relates to novel lightweight cellular cement compositions, methods of preparing such compositions and methods of casting the compositions into lightweight high strength structural members.