Abstract: A method and apparatus for injecting solid particles such as dry ice into an airstream using an airlock having a spherical valve member with spaced through ports and rotatable between an annular seal on one side of the spherical member for feeding the particles to the fluid stream chamber with an annular seal on the opposite side for sealing a particle feed chamber. The airlock device is useful for sealing fluid stream pressure of about 133 Kg/m2 and temperatures of about 350° R.

Abstract: A method and apparatus for injecting solid particles such as dry ice into an airstream using an airlock having a spherical valve member with spaced through ports and rotatable between an annular seal on one side of the spherical member for feeding the particles to the fluid stream chamber with an annular seal on the opposite side for sealing a particle feed chamber. The airlock device is useful for sealing fluid stream pressure of about 133 Kg/m2 and temperatures of about 350° R.

Abstract: A method and device for forming slabs of dry ice is shown. A dry ice extruding machine has been modified with a die that has a slot for extruding a slab of dry ice therethrough. The slot is blocked until a puck is formed in an end of a forming chamber of the dry ice extruding machine. The block is then removed and dry ice extruded to a desired length and then broken to give a slab of dry ice. The last step is repeated over and over as the extruded portion reaches the desired length to give the number of slabs wanted.

Abstract: An apparatus for removing surface coverings comprises a feeder device capable of providing a supply of dry ice pieces, a pellet-size reducer operatively associated with the feeder device to receive dry ice pieces from said feeder device and reduce the size of the dry ice pieces to nominal diameters less than 1 mm, and a blast gun connected to the pellet-size reducer and adapted for operative communication with an associated supply of flowing gas. The blast gun incorporates a venturi to entrain the reduced-sized dry ice pieces into the flowing gas and directs the flowing gas and dry ice pieces to an associated surface covering to be removed. Preferably, the pellet-size reducer is a knife- or disc-type grinding mill. In one embodiment, the grinding mill is adjustable for controlling the size of the dry ice particles supplied to the blast gun. The apparatus preferably includes a humidity controller to suppress static charges caused by the interaction of the dry ice particles with the surface being blasted.

Abstract: A pneumatic apparatus produces high density dry ice pellets without external electric or hydraulic energy. The apparatus operates solely on compressed air for reduced capital and maintenance costs and for portability to harsh or remote locations. An air-over-oil booster is connected to a pelletizing cylinder which is in turn connected to a source of liquid CO.sub.2 through an electronic controller. The controller sequences a set of fluid valves for operation of both the booster and pelletizing cylinder.

Abstract: A pneumatic pellet transportation apparatus loads a predetermined quantity of dry ice pellets into an empty container while simultaneously evacuating the containers of dead air. The apparatus includes an aerator for fluidizing the dry ice pellets into a moving stream of compressed air. A container interface unit directs the fluidized dry ice pellets into an opening provided in the container. A method of using the pneumatic pellet transportation apparatus includes deactivating an auger well before the aerator is deactivated in order to clear the vacuum insulated transport conduit for efficient utilization of dry ice pellet resources.

Abstract: The invention pertains to an apparatus and process for producing predetermined size and density dry ice pellets used for blasting operations. Liquid carbon dioxide is compressed into solid dry ice within a computer controlled piston and cylinder extruder. The applied pressure by the piston is controlled to produce solid dry ice at a predetermined pressure while forward movement is controlled in an intermittent start-stop cycle where the "start" mode controls the length of the dry ice extrudate while the "stop" mode enables an exterior cutting device to cut the extrudate to the predetermined length. Preferred pellets exhibit uniform dimensions such as cylindrical or cubic pellets.

Abstract: A goal-scoring game is played on a convex playing field having an apex, a periphery lower than the apex, and a spaced apart plurality of goals adjacent the periphery for receipt of game pieces. A plurality of movable game pieces are provided for movement about the field and into the goals. Player-operated impacting flippers are disposed adjacent to and associated with each of the goals, for impacting one of the game pieces to drive the impacted game piece away from the associated goal. A disperser is disposed over the field for storing a plurality of the game pieces and dropping them one at a time in rapid succession precisely onto the apex of the field.

Abstract: This invention relates to a carbon dioxide blast cleaning system for propelling dry-ice pellets by cryogens, namely high pressure nitrogen, helium and/or oxygen, against a surface being cleaned. Carbon dioxide pellets, in a pellet hopper, a blast unit and a blast gun are located at a blast site near the surface being cleaned. A portable cryogenic liquid nitrogen, liquid helium and/or liquid air tank with an ambient air vaporizer is also located at or near the blast site. Cryogenic liquid nitrogen, liquid helium and/or oxygen flow through the ambient air vaporizer to the liquid and is vaporized to form a high pressure gas. The high pressure, cryogenic gas is then brought into the blast unit and mixed with the pellets. The mixture of the high pressure gas and the pellets exit the gun nozzle at high velocities to blast the surface being cleaned.

Abstract: A structure having a metal body with a plurality of intersecting cavities and a consolidated corrosion resistant powdered metal lining and metallurgically engaging the walls of the intersecting cavities.

Abstract: An improved forging billet of dual alloys and an improved method for forging a dual alloy billet. The billet is cylindrical in shape having an outer tubular portion of one alloy and another alloy filling the central opening through the tubular portion, the ends of the billet include a radial flange of the tubular alloy extending a short distance outward at each end of the billet and having a skirt extending from the outer end of the radial flange axially away from the body of the billet to form a circular opening at each end of the billet which has at least as large a diameter as the outer diameter of the outer tubular portion, and a sandwich structure positioned within each of said circular opening including a plurality of layers of a powdered lubricant, preferably boron nitride lubricant, separated by foil layers, preferably a high purity nickel foil.

Abstract: A racket for playing ball games especially with foam balls. An ankh (without the cross) shaped inner inflatable portion is covered by an outer racket shaped envelope. The toroidal portion of the ankh stretches the outer envelope to develop a rigid racket. The outer, stretched, envelope's surfaces are used as the ball striking surfaces. A squeezable pump located in the handle is used for inflating the racket. A manually operated valve located in the handle is used to deflate the racket for convenient storage.

Abstract: A process for producing a composite billet employing powder metallurgical techniques in which a first alloy powder of a preselected composition is compacted in a tubular container producing a preliminarily compacted tubular mass which thereafter is finished on the interior surface thereof to desired final dimensions. The resultant tubular mass is placed in a second container and the core thereof is filled with a powder of a desired second alloy composition and the contents are sealed. The second alloy powder is subsequently hot compacted to a density approaching 100 percent theoretical density without incurring any appreciable distortion or dimensional change of the tubular mass. Thereafter, the preliminary composite compacted billet is subjected under elevated temperature to an axial extrusion step producing a final composite extruded billet having a concentric outer layer of a first alloy and an inner core layer of a second alloy metallurgically bonded together.

Abstract: A toy building which is easily carried and yet which can form a larger size play unit. A first floor part 3 of the building is slidably received within a ground floor part 1. Clip elements 7 include lugs 21 and 23 slidable on rails 19 engage with respective projections 33 and 37 to locate the upper part 3 in its elevated position. The lug 23 is engageable with an upper projection 35 for locating the parts 1 and 3 in their collapsed positions.

Abstract: The method of forming a lining in the cavities of a body by application of powdered metal consolidated and bonded thereon by a hot isostatic pressing process. A space lining the cavities in the body is provided by tubular members, one intersecting with the other or in close spaced relation thereto, powdered metal fills the space, a vacuum is drawn on the space, the body is subjected to forming conditions and then the body cavities are machined to their final shape with such machining generally removing the tubular members.

Abstract: An improved forged steel structure lined with a corrosion resistant metal in which the lining and body are forged together. The improved method includes the steps of securing a bar of corrosion resistant metal within an alloy steel tube to form a billet, forging the billet to the desired shape with sufficient corrosion resistant metal to line at least one of the cavities of the desired shape and machining the forging to produce the desired lined structure. The amount of alloy steel and corrosion resistant metal in the billet being preselected to provide the desired lining without substantially weakening the structure.

Abstract: An electromechanically controlled board game for two players, each of which has a set of playing pieces which are advanced on a board in rank or file increments to attack pieces of the opposing player. The pieces are so configured that the relative value of each piece is visible only to the holder of the piece during play. An attacking piece is compared in value with the piece attacked by comparing a four bit code assigned to each piece with a corresponding code assigned to the piece attacked. The lower valued piece is considered captured, and is retired without disclosure of its relative value to the opposing player. Each side has one piece designated "flag" the object of the game being to capture the flag of the opposing side.

Abstract: The method of forming a lining in the cavities of a body by application of powdered metal consolidated and bonded thereon by a hot isostatic pressing process. A space lining the cavities in the body is provided by tubular members, one intersecting with the other or in close spaced relation thereto, powdered metal fills the space, a vacuum is drawn on the space, the body is subjected to forming conditions and then the body cavities are machined to their final shape with such machining generally removing the tubular members.