Abstract: A method mixes and transfers a bone filling material. The method makes use of a receptacle for receiving components in an unmixed condition. A mixing element can be inserted into the receptacle to mix the components. An actuator having a drive member and a driven member is removably coupled to the mixing element.

Abstract: Coating production systems and methods which include ultrasonic dispersion and active cooling. The system includes a mixing reservoir and an ultrasonic disperser for ultrasonically dispersing an additive with another coating component within the mixing reservoir. The system also includes a heat exchanger in communication with the mixing reservoir to receive a mixture of the additive and another coating component from the mixing reservoir. The mixture is cooled by thermal energy transfer from the mixture to the heat exchanger. The cooled mixture is returned to the mixing reservoir.

Abstract: A method and an arrangement for successively feeding batches into a mixing vessel under partial vacuum for the preparation of bone cement. The arrangement includes an inner container communicating with the atmosphere and with the mixing vessel, which container is so arranged as to enclose a glass ampoule containing a liquid bone cement component and, on the other hand, a device for opening the ampoule so that its contents can be sucked into the mixing vessel under partial vacuum. An outer container encloses the inner container at least partially, and is arranged to communicate with the mixing vessel. The inner container, and the outer container, define a space filled with a proportional quantity of a second bone cement component, which is in powder form.

Abstract: A microarray assay system using an array-of-arrays plate mounted on the top surface of a vacuum fixture, and an automatic handling system that handles the plate and fixture assembly. The A2 plate includes a tray formed of a flexible material and a rigid frame for mounting on the fixture. The fixture has a plurality of orifices opening at the top surface and connected to a vacuum source to create a negative pressure to hold the flexible plate against the top surface of the fixture. The automatic handling systems that can be used with the plate and fixture assembly include a microarray printing machine, liquid handling robot, hybridization and incubation devices, and microarray imaging devices.

Abstract: A food marinating apparatus includes a substantially cylindrical canister and a base unit including a motor, a plurality of rollers, a vacuum pump, and a control panel. The base unit is operable to rotate the canister thereon. The vacuum pump is provided for reducing the ambient pressure inside of the vessel, to improve marinade absorption by the food. Food such as meat or fish will receive marinade more quickly under low pressure than under atmospheric pressure, and additionally, by rotating the containment vessel, the food is agitated in the presence of the marinade, for a higher degree of marinade absorption.

Abstract: A food marinating apparatus includes a substantially cylindrical canister and a base unit including a motor, a plurality of rollers, a vacuum pump, and a control panel. The base unit is operable to rotate the canister thereon. The vacuum pump is provided for reducing the ambient pressure inside of the vessel, to improve marinade absorption by the food. Food such as meat or fish will receive marinade more quickly under low pressure than under atmospheric pressure, and additionally, by rotating the containment vessel, the food is agitated in the presence of the marinade, for a higher degree of marinade absorption.

Abstract: The present system comprises an apparatus and a process for continuously dispersing fine particles in a liquid. The apparatus comprises a mixer that has at least one inlet for receiving the fine particles and liquid and an outlet. The mixer further comprises a barrel that has an inlet for accepting the fine particles and an outlet for dispersing the fine particles and a tank for holding the liquid. The tank has a top surface in which the barrel is disposed such that the outlet of the barrel is disposed under the surface of the liquid. An inlet of a vacuum centrifuge is coupled to the outlet of the mixer to receive a mixture of liquid and fine particles. A surge tank is coupled to an outlet of the vacuum centrifuge, wherein the mixture is dispersed from an outlet of the surge tank.

Abstract: Apparatus and methods for mixing and dispensing components. The methods and apparatus of the invention are particularly advantageous to manually mix the components of radiopaque bone cement and inject the resulting radiopaque bone cement into skeletal structures. The manually actuated apparatus of the invention comprises: (1) a sealed mixing chamber for mixing components; (2) a dispensing chamber isolated from the sealed mixing chamber; (3) a controllable portal to open a flow path between the sealed mixing chamber and the dispensing chamber so that the dispensing chamber can receive the mixed components after they are mixed; and (4) a drive mechanism associated with the dispensing chamber to force the mixed contents from the dispensing chamber.

Abstract: A mixing assembly for mixing bone cement includes a housing, a lid, a handle, and two mixing paddles, a first and a second mixing paddle. The lid is removably attachable to the housing. The handle has a portion that extends through the lid and that is rotatable in a first rotational direction. The first mixing paddle is operatively coupled to the portion of the handle. As a result, the first mixing paddle rotates with the portion of the handle in the first rotational direction. The second mixing paddle is operatively coupled to the first mixing paddle for rotating opposite the portion. As such, when the portion of the handle and the first mixing paddle rotate in the first rotational direction, the second mixing paddle rotates in a second rotational direction that is opposite the first rotational direction.

Abstract: A method of determining liquid absorption of an aggregate comprises providing a shaker apparatus, a vacuum source and a container; placing a sample of the aggregate in the container; adding liquid to the container sufficient to reach a calibration mark on the container; weighing the sample and liquid; mounting the container to the shaker apparatus; connecting the vacuum source to the container; agitating the sample and liquid with the shaker apparatus; applying a vacuum to the sample and liquid with the vacuum source; after the agitation and vacuum steps, adding liquid to the container sufficient to again reach the calibration mark on the container; again weighing the sample and liquid; and subtracting the initial weight of the sample and liquid from the final weight of the sample and liquid in order to determine the liquid absorption of the aggregate.

Abstract: Apparatus and methods for mixing and dispensing components. The methods and apparatus of the invention are particularly advantageous to mix the components of radiopaque bone cement and inject the resulting radiopaque bone cement into skeletal structures. The apparatus of the invention comprises: (1) a sealed mixing chamber for mixing components; (2) a dispensing chamber isolated from the sealed mixing chamber; (3) a controllable portal to open a flow path between the sealed mixing chamber and the dispensing chamber so that the dispensing chamber can receive the mixed components after they are mixed; and (4) a drive mechanism associated with the dispensing chamber to force the mixed contents from the dispensing chamber.

Abstract: A container assembly for mixing materials having a base defining a mixing chamber for mixing the materials and a cover mounted to the base covering the mixing chamber. A sealing portion depends from the cover and engages an inner wall of the base. The sealing portion is flexible and angled outwardly such that during the engagement of the sealing portion with the inner wall, the sealing portion flexes and conforms to the inner wall to seal the mixing chamber. In addition, a first locking device is disposed on the base and a second locking device is disposed on the cover. A lifting mechanism is disposed on one of the base and cover for automatically lifting the cover relative to the base as the cover is being removed from the base for preventing a discharge of material from the mixing chamber.

Abstract: A method for conditioning cooled used moulding sand retaining moulding sand binder in a mixer (1), wherein the cooled used moulding sand is heated to at least a minimum temperature, moisturized by providing water or water vapor through holes in an agitator and subsequently cooled in the mixer from the minimum temperature using the effect of a vacuum.

Abstract: A bone cement mixing apparatus includes a bowl, an attachable/detachable lid, and a handle extending from the bowl. The bowl incorporates a bone cement vapor removal system that allows the extraction of bone cement vapors or fumes even after the lid has been detached from the bowl. Such extraction of vapors may be continuous. The vapor removal system is coupled to a vacuum source. The handle is ergonomically shaped and incorporates vacuum tubing that couples the bone cement vapor removal system of the bowl with the vacuum source.

Abstract: The apparatus is a mixing and dispensing device for orthopaedic bone cement, comprising an introducer funnel and a mixing syringe body. A mixing shaft and paddle arrangement extends through the funnel and mixing chamber, the paddle having a profile matching the shape of the funnel, in the introducer funnel.

Abstract: The present invention relates to a device at mixing devices for mixing pulverulent and liquid substances with each other for the manufacture of medical products, wherein a displaceable piston means (17) has at least one groove (22) extending around said piston means (17) and at least one sealing ring (23) is located in said groove (22). At least one connecting passage (22e) is provided for preventing a liquid substance (21) from generating or building up such a pressure in an inner space (22d) in the groove (22) within or behind the sealing ring (23) that said pressure presses the sealing ring (23) in a direction outwards (F) relative to the groove (22) towards a surrounding wall (1a) of the mixing device (1) and prevents or counteracts flow of the liquid substance (21) past the piston means (17) when said piston means (17) is displaced.

Abstract: A device for preparing moulding sand. The device includes a mixer configured to operate under at least a partial vacuum and at least one feeder to introduce components to be mixed. An inlet in the mixer is of sufficient size to allow rapid introduction of the components into the mixer from the feeder. The combination of large inlet opening and a pressure differential between the mixer and the feeder significantly reduces the time required to fill the mixer. In addition, the presence of the pressure differential made possible by the vacuum in the mixer reduces the likelihood that airborne contaminants resident in the mixer will migrate outside the mixer. Optional moveable conveyor chutes minimize contact of airborne contaminants with adjacent equipment, while optional mixing tools facilitate the introduction of powdered additives into the mixer.

Abstract: There is provided a mixer for a capsule for dental restoration material used for mixing a powder component and a liquid component in a capsule accommodating therein the powder component and the liquid component for restoration of a tooth in the dental remedy field, by rendering a mixing compartment in vacuo so as to make it in a good state where the mixture does not substantially contain air bubbles.

Abstract: An apparatus for degassing plastic materials, e.g., high molecular weight polycarbonate solutions, is described. The apparatus includes a double-shaft extruder having a length-to-diameter ratio of less than or equal to 40, which comprises: (i) two co-rotating and meshing shafts; (ii) an intake opening; and (iii) upstream and downstream portions relative to the intake opening. The shafts of the extruder are designed with a double lead in a degassing zone, and with a triple lead in a pressure build-up zone. Each of the degassing and the pressure build-up zones are down-stream from the intake opening, and the pressure build-up zone is further down-stream than the degassing zone. Also described is a process for degassing plastic materials, which involves providing the described double-shaft co-rotating extruder, into which plastic material is fed, processed and degassed.

Abstract: A method and apparatus for mixing viscous material, includes placing ingredients of the viscous material within a vessel. An air tight seal is created about the vessel. A vacuum is pulled on the vessel, and the ingredients are mixed within the vessel to form the viscous material while under vacuum. The vacuum is sufficient to reduce the amount of total air content in viscous material to between 0.9% and 0.1% by volume prior to an air entraining agent being added to the viscous material. Once air entraining agent is added, further mixing of the ingredients forms entrained air content in the final viscous material, while the amount of entrapped air in the final viscous material remains reduced.

Abstract: Apparatus and methods for mixing and dispensing components. The methods and apparatus of the invention are particularly advantageous to manually mix the components of radiopaque bone cement and inject the resulting radiopaque bone cement into skeletal structures. The manually actuated apparatus of the invention comprises: (1) a sealed mixing chamber for mixing components; (2) a dispensing chamber isolated from the sealed mixing chamber; (3) a controllable portal to open a flow path between the sealed mixing chamber and the dispensing chamber so that the dispensing chamber can receive the mixed components after they are mixed; and (4) a drive mechanism associated with the dispensing chamber to force the mixed contents from the dispensing chamber.

Abstract: A preparation and application device for implant materials consisting of at least one powder or granulate component and one liquid component, which are to be prepared immediately before use, is disclosed. The device comprises a first container which holds the powder or granulate component in a sterile, closed-off manner; and a second container which holds the liquid component in a sterile, closed-off manner and which can be connected to the first container. A mixing shaft which is hollow and located on a mixing mechanism is guided out of the first container is hollow and joins a hand pump for producing negative pressure at its external end. A measuring device which indicates the negative pressure can be connected to the first container and the housing of the hand pump is configured in such a way that it is suitable for use as a handle for moving the mixing shaft.

Abstract: Vacuum mold making and casting equipment is desirable for producing a higher quality mold when casting small parts in polyurethane resin. Specifically, this equipment is aimed at minimizing entrapped air within such parts by applying suction to create a vacuum. The air could be removed during two steps in the casting process. Initially, air that becomes entrapped in the compound during the mixing phase can be evacuated by sealing the mixing bowl with an airtight lid and applying suction through a hose connected at the top of the lid. After the compound has been poured into the cast, this same equipment can be used to once again remove any entrapped air. By removing entrapped air, higher quality molds and cast materials can be achieved. A supply of disposable mixing cups would be included with the equipment. Although the cups would all feature the same diameter and hemispherical bottom, they would be offered in a variety of capacities and would be marked with volumetric graduations.

Abstract: A bone cement mixing and delivery assembly is disclosed for mixing a powdered copolymer and a liquid monomer to form a bone cement and delivering the bone cement. The assembly includes a cartridge having a distal end and a proximal end and defining a mixing chamber between the distal end and the proximal end. A transfer mechanism having a cap and a stem supporting a piston and a plunger is connected to the distal end. The transfer mechanism includes a first advancement mechanism for advancing the piston and plunger in unison and a second advancement mechanism for moving the plunger independent of the piston. The assembly further includes a removable handle having a shaft for attachment of a mixing blade and a quick-release connector and a release button for locking and unlocking the mixing blade from the removable handle.

Abstract: There is provided a mixer for a capsule for dental restoration material used for mixing a powder component and a liquid component in a capsule accommodating therein the powder component and the liquid component for restoration of a tooth in the dental remedy field, by rendering a mixing compartment in vacuo so as to make it in a good state where the mixture does not substantially contain air bubbles.

Abstract: There is provided a mixer for a capsule for dental restoration material used for mixing a powder component and a liquid component in a capsule accommodating therein the powder component and the liquid component for restoration of a tooth in the dental remedy field, by rendering a mixing compartment in vacuo so as to make it in a good state where the mixture does not substantially contain air bubbles.

Abstract: The invention relates to a preparation and application device for materials which are to be prepared as a paste-like, flowable mass from at least one powder or granulate component and one liquid component, especially bone cement, with an elongated mixing cylinder for receiving the components to be mixed, comprising in one end region a sealable through-opening that can optionally be provided with a discharge unit for the paste-like material to be prepared, and a piston which can be inserted into the other, opposite, open end. The piston is displaceable in the cylinder and seals against the inner wall of the cylinder. The piston is penetrated by an elongated mixing shaft sealed against the piston, and a mixing mechanism is disposed at the cylinder inside-end of the mixing shaft and a handle disposed at the cylinder outside-end of the mixing shaft.

Abstract: A bone cement mixing and delivery assembly is disclosed for mixing a powdered copolymer and a liquid monomer to form a bone cement and delivering the bone cement. The assembly includes a cartridge having a distal end and a proximal end and defining a mixing chamber between the distal end and the proximal end. A transfer mechanism having a cap and a stem supporting a piston and a plunger is connected to the distal end. The transfer mechanism includes a first advancement mechanism for advancing the piston and plunger in unison and a second advancement mechanism for moving the plunger independent of the piston. The assembly further includes a removable handle having a shaft for attachment of a mixing blade and a quick-release connector and a release button for locking and unlocking the mixing blade from the removable handle.

Abstract: A mixer for capsule for dental restoration material to mix a powder component and a liquid component within a mixing compartment of a capsule having an air-permeable filter without passing the powder and liquid components placed in a site connecting the inside of the mixing compartment to the outside into a mixture without air bubbles quietly, quickly and efficiently, includes a capsule holding compartment for holding the capsule such that the air within the mixing compartment can be discharged out from the air-permeable filter, a rotating unit of capsule holding compartment for subjecting the capsule holding compartment itself to a circular motion in the state that the longitudinal direction of the capsule holding compartment is kept in a constant direction, a driving unit for driving the rotating unit of capsule holding compartment, and a vacuum device connected to the capsule holding compartment.

Abstract: Apparatus and methods for mixing and dispensing components. The methods and apparatus of the invention are particularly advantageous to mix the components of radiopaque bone cement and inject the resulting radiopaque bone cement into skeletal structures. The apparatus of the invention comprises: (1) a sealed mixing chamber for mixing components; (2) a dispensing chamber isolated from the sealed mixing chamber; (3) a controllable portal to open a flow path between the sealed mixing chamber and the dispensing chamber so that the dispensing chamber can receive the mixed components after they are mixed; and (4) a drive mechanism associated with the dispensing chamber to force the mixed contents from the dispensing chamber.

Abstract: An apparatus and method for dispersing solids into a liquid. The solids may be any particulate material, ranging from cohesive to free flowing. The apparatus and method use an auger to deliver the solids from a hopper to a mixer, where the solids are dispersed into one or more liquids. Typically a vacuum is created in the mixer, or other differential pressures may occur between the hopper and mixer. The apparatus and method provide a delivery rate of the solids which is substantially controlled by the auger rotational speed and substantially independent of the vacuum or other differential pressure at certain auger rotational speeds.

Abstract: A method of determining liquid absorption of an aggregate comprises providing a shaker apparatus, a vacuum source and a container; placing a sample of the aggregate in the container; adding liquid to the container sufficient to reach a calibration mark on the container; weighing the sample and liquid; mounting the container to the shaker apparatus; connecting the vacuum source to the container; agitating the sample and liquid with the shaker apparatus; applying a vacuum to the sample and liquid with the vacuum source; after the agitation and vacuum steps, adding liquid to the container sufficient to again reach the calibration mark on the container; again weighing the sample and liquid; and subtracting the initial weight of the sample and liquid from the final weight of the sample and liquid in order to determine the liquid absorption of the aggregate.

Abstract: A method of bone cement preparation from a polymeric powder and a liquid component including a polymerisable monomer or comonomer by the action of a catalytic system. Particles of the powder are packed in a powder container having an inlet and an outlet port, while the liquid component is held in a liquid container. The liquid container is connected to te inlet port and a vacuum source is connected to the outlet port. A voided space between the powder particles is flooded by the liquid component that flows form the inlet port toward the outlet port under the influence of the vacuum source.

Abstract: A bone cement mixing device has a canister which is modular in design and constructed from a transparent material. The mixing device further has a mixing head assembly having a crank which is operatively coupled to a mixing blade via a gear train. The gear train is configured to drive the mixing blade in a reciprocating manner including the varying of the angular velocity, direction of travel, and angular distance of travel of the blade while the crank is rotated at a constant velocity and direction. The mixing blade has a fluid passage defined therein which allows the liquid cement component to be delivered at various locations within the mixing chamber of the canister. A method of mixing bone cement is also disclosed.

Abstract: Methods for reducing the number and/or size of gas bubbles in a material are disclosed. The disclosed methods involve subjecting materials to pressure for a period of time. The methods have been found to be useful in the preparation of dental composites and dental structures prepared from those composites. Materials produced using the disclosed methods can have enhanced structural and/or aesthetic features.

Abstract: A multi-component handling and delivering system, and its methods of use, comprising a fully integrated structure for combining chemical and other components. The system eliminates the requirement for independent component transfer and atmospheric escape of any chemical vapors during handling and combining. The invention is useful to combine bone cement components (i.e., bone cement power and liquid monomer) to form bone cement.

Abstract: A bone cement mixing device has a canister which is modular in design and constructed from a transparent material. The mixing device further has a mixing head assembly having a crank that is operatively coupled to a mixing blade via a gear train. The gear train is configured to drive the mixing blade in a reciprocating manner including the varying of the angular velocity, direction of travel, and angular distance of travel of the blade while the crank is rotated at a constant velocity and direction. The mixing blade has a fluid passage defined therein which allows the liquid cement component to be delivered at various locations within the mixing chamber of the canister. A method of mixing bone cement is also disclosed.

Abstract: A method and a device for preparation of bone cement. The constituent components of bone cement are mixed under vacuum in a closed mixing chamber, which has a vacuum connection (4), a moveable wall section (2), a device arranged to maintain the moveable wall section (2) in its initial position during the mixing process, an extrusion opening located opposite to the moveable wall section (2) and a device (9) arranged to openably seal the extrusion opening. The extrusion is performed by the moveable wall section (2) being brought to move towards the extrusion opening, by applying a force against the moveable wall section (2) using an extrusion tool (12). The moveable wall section (2) is set free after mixing is finished and thereafter forced towards the extrusion opening for compression of bone cement while the extrusion opening is sealed by the sealing device (9).

Abstract: A bone cement mixing apparatus includes a bowl, an attachable/detachable lid, and a handle extending from the bowl. The bowl incorporates a bone cement vapor removal system that allows the extraction of bone cement vapors or fumes even after the lid has been detached from the bowl. Such extraction of vapors may be continuous. The vapor removal system is coupled to a vacuum source. The handle is ergonomically shaped and incorporates vacuum tubing that couples the bone cement vapor removal system of the bowl with the vacuum source.

Abstract: A mixing assembly for mixing bone cement includes a housing, a lid, a handle, and two mixing paddles, a first and a second mixing paddle. The lid is removably attachable to the housing. The handle has a portion that extends through the lid and that is rotatable in a first rotational direction. The first mixing paddle is operatively coupled to the portion of the handle. As a result, the first mixing paddle rotates with the portion of the handle in the first rotational direction. The second mixing paddle is operatively coupled to the first mixing paddle for rotating opposite the portion. As such, when the portion of the handle and the first mixing paddle rotate in the first rotational direction, the second mixing paddle rotates in a second rotational direction that is opposite the first rotational direction.

Abstract: In the case of thickening a feed resin without pre-drying, a device is taught to enhance the thickening effect. The device includes a chamber 4 having a mixing rotor therein for continuously mixing a resin between a feed port 2 and a discharge port 3. A plurality of vent ports 7 connected to vacuum pumps 8, 9 are provided for reducing the pressure in the chamber. An element, e.g. a screw feeder 10, is provided for introducing a viscosity-increasing chemical agent into the chamber. The screw feeder is isolated from the reduced pressure areas of the chamber by elements 35, e.g. reverse screw flights of the rotor. In operation, feed resin from a hopper 6 enters the chamber through port 2 and is dehydrated while being continuously mixed in a drying section 14 via vents 7. After addition of the chemical agent, the resin is continuously mixed in a thickening section 15 while being deaerated.

Abstract: A bone cement mixing apparatus comprises a cylindrical syringe body which functions as a mixing chamber, a mixing element rotatably mounted in the mixing chamber and a drive for causing rotation of the mixing element. The drive includes a handle which is axially movable relative to the mixing chamber and a gear mechanism which couples the handle of the mixing element and translates linear handle motion into rotary mixing element motion. The drive is supported by a chamber lid which engages the syringe body and the lid and drive may be detachable from the syringe body and from the mixing element thereby allowing the lid assembly and drive to be reused.

Abstract: A base for a disposable surgical cement mixing system includes a support member and a vacuum source. The support member is configured to support cement within a mixing chamber. The vacuum source is carried by the support member. The vacuum source is operative to impart a relative vacuum within the mixing container during mixing of the cement.

Abstract: The apparatus is a mixing and dispensing device for orthopaedic bone cement, comprising an introducer funnel (1) and a mixing syringe body (25). A mixing shaft (4) and paddle (3) arrangement extends through the funnel (1) and mixing (2) chamber, the paddle (3) having a profile matching the shape of the funnel (1), in the introducer funnel (1).

Abstract: A mixer for capsule for dental restoration material to mix a powder component and a liquid component within a mixing compartment of a capsule having an air-permeable filter without passing the powder t and liquid components placed in a site connecting the inside of the mixing compartment to the outside into a mixture without air bubbles quietly, guickly and efficiently, is constituted of a capsule holding compartment for holding the capsule such that the air within the mixing compartment can be discharged out from the air-permeable filter, a rotating unit of capsule holding compartment for subjecting the capsule holding compartment itself to a circular motion in the state that the longitudinal direction of the capsule holding compartment is kept in a constant direction, a driving unit for driving the rotating unit of capsule holding compartment, and a vacuum device connected to the capsule holding compartment.

Abstract: By providing a fluid transfer assembly, two components forming bone cement are maintained separately from each other until actual intermixing thereof for use is desired, with the liquid monomer component being completely dispensed from a sealed unit directly into the mixing vessel in a closed loop manner, without exposure thereof to the user and without breakage of the container holding the liquid monomer, and a unique, multi-component, product handling and delivering system is achieved. In accordance with the present invention, the fluid transfer assembly is constructed for cooperating with the sealed vial or tube containing the liquid monomer and the mixing vessel for completely extracting all of the liquid monomer from the vial/tube in a closed loop operation and directly delivering the liquid monomer into the mixing vessel containing the dry powder. This transfer operation is achieved upon demand by the user, while preventing the liquid monomer from being exposed to the user or to the surrounding area.

Abstract: An apparatus and method for dispersing solids into a liquid. The solids may be any particulate material, ranging from cohesive to free flowing. The apparatus and method use an auger to deliver the solids from a hopper to a mixer, where the solids are dispersed into one or more liquids. Typically a vacuum is created in the mixer, or other differential pressures may occur between the hopper and mixer. The apparatus and method provide a delivery rate of the solids which is substantially controlled by the auger rotational speed and substantially independent of the vacuum or other differential pressure at certain auger rotational speeds.

Abstract: The present invention relates to a device at mixing devices for mixing pulverulent and liquid substances with each other for the manufacture of medical products, wherein a displaceable piston means (17) has at least one groove (22) extending around said piston means (17) and at least one sealing ring (23) is located in said groove (22). At least one connecting passage (22e) is provided for preventing a liquid substance (21) from generating or building up such a pressure in an inner space (22d) in the groove (22) within or behind the sealing ring (23) that said pressure presses the sealing ring (23) in a direction outwards (F) relative to the groove (22) towards a surrounding wall (1a) of the mixing device (1) and prevents or counteracts flow of the liquid substance (21) past the piston means (17) when said piston means (17) is displaced.

Abstract: A bone cement mixing and delivery assembly is disclosed for mixing a powdered copolymer and a liquid monomer to form a bone cement and delivering the bone cement. The assembly includes a cartridge having a distal end and a proximal end and defining a mixing chamber between the distal end and the proximal end. A transfer mechanism having a cap and a stem supporting a piston and a plunger is connected to the distal end. The transfer mechanism includes a first advancement mechanism for advancing the piston and plunger in unison and a second advancement mechanism for moving the plunger independent of the piston. The assembly further includes a removable handle having a shaft for attachment of a mixing blade and a quick-release connector and a release button for locking and unlocking the mixing blade from the removable handle.

Abstract: By providing a fluid transfer assembly, two components forming bone cement are maintained separately from each other until actual intermixing thereof for use is desired, with the liquid monomer component being completely dispensed from a sealed unit directly into the mixing vessel in a closed loop manner, without exposure thereof to the user and without breakage of the container holding the liquid monomer, and a unique, multi-component, product handling and delivering system is achieved. In accordance with the present invention, the fluid transfer assembly is constructed for cooperating with the sealed vial or tube containing the liquid monomer and the mixing vessel for completely extracting all of the liquid monomer from the vial/tube in a closed loop operation and directly delivering the liquid monomer into the mixing vessel containing the dry powder. This transfer operation is achieved upon demand by the user, while preventing the liquid monomer from being exposed to the user or to the surrounding area.