Abstract: A drug delivery device having a base member defining a skin-contacting surface, a syringe serving as a reservoir for the drug, and means for expelling drug from the syringe. The syringe is connected to the base member such that the longitudinal axis of the syringe is substantially parallel to the skin surface. A delivery needle is in communication with the syringe. The needle has an angled bend which directs the tip of the needle substantially perpendicular to the skin-contacting surface. In use, the tip of the needle is adapted to penetrate the skin of the subject.

Abstract: A digital fluid delivery and aspiration apparatus with a mechanical de-amplifier for the delivery or removal of discrete volumes of fluidic material from a surgical site. The apparatus has a syringe with a plunger designed to be powered by a pneumatic air supply system. A ratcheting mechanism attached to a pneumatic piston by a mechanical linkage causes the plunger of the syringe to inject discrete doses of the fluidic material into the surgical site or remove discrete amounts of fluidic material from the surgical site. The mechanical linkage increases the force provided to the plunger by the movement of the piston and also de-amplifies the movement of the piston into a lesser movement of the plunger.

Abstract: A gas-powered, single-use, needle-less hypodermic jet injection device includes a hand-held injector, and a drug injection cartridge which provides a cylinder of liquid medication to be injected, an injection orifice, and an injection piston. Forceful movement of the injection piston in the cylinder causes an injection jet of medication to be expelled from the injection orifice. The injection device also includes a hermetically sealed gas pressure capsule which remains sealed until the moment of injection and powers the jet injection after opening of this cartridge.

Abstract: An injection device for injecting a filling into a wall includes a filling housing having a nozzle, and a plunger slidably engaged in the housing for drawing and injecting the filling relative to the housing. One or more vacuuming housings are secured to the filling housing and each has a plunger for vacuuming the vacuuming housing. The vacuuming housing plunger may force the plunger of the filling housing to inject the filling into the cracks of the walls. The plungers may be secured to the respective housing and may be disengaged from the housing when required.

Abstract: A liquid medicine injection apparatus which is capable of injecting a liquid medicine at an accurate flow rate and which does not require an excessively strong force for filling the apparatus with the liquid medicine. The apparatus includes a barrel 1 provided with a port 11 at the distal end thereof and a shaft 12 extending along the longitudinal axis thereof, a hollow plunger 2 provided at its distal end with a first gasket 3 inserted into the barrel 1 while allowing the shaft 12 of the barrel to pass therethrough, and also provided at the proximal end thereof with a closing member 4 having a vent hole 41; a second gasket 5 connected to the proximal end of the shaft 12; and outside air releasing means 6 for allowing the space between the first and second gaskets to communicate with the outside air.

Abstract: A needle-less hypodermic jet injection device includes a hand-held injector, and a drug injection cartridge which provides a cylinder of liquid medication to be injected, an injection orifice, and an injection piston forceful movement of which in the cylinder causes an injection jet of medication to be expelled from the orifice. The injection device also includes a gas pressure capsule which powers the jet injection and which also automatically resets the injection device during an injection in order to prepare it for a subsequent injection. A multi-function component of the device is effective to place it in a safe condition allowing the device to be prepared for a next injection, and to place the device in a ready condition for allowing a jet injection to be conducted by use of the device.

Abstract: A pneumatically operated veterinary medicinal pellet implanter utilizes pressurized air to drive an impeller for dispensing medicinal pellets through a needle on an end of the implanter and into a cavity created by the needle under the skin of an animal to be treated. The pressurized air source may also be utilized to retract the impeller after dispensing of the pellets. The impeller is part of a piston slidingly secured within a pneumatic cylinder. Pressurized air is selectively and alternatingly supplied to the front and rear and rear of the cylinder for advancing the impeller between retracted and extended positions respectively. The pressure of the air supplied to the rear of the cylinder for driving the impeller is reduced relative to the pressure of the air supplied to the front of the cylinder for retracting the impeller.

Abstract: The present disclosure describes a system wherein a drug or other fluid to be delivered to a specific desired location within the body is stored in a reservoir that is directly displaced by a force to infuse the drug from the device into the patient. Several specific methods are used to displace the reservoir, including, generally, hydraulic displacement, mechanical screw-type displacement, and spring force displacement of the fluid reservoir.

Abstract: An applicator (10) to deliver a liquid via a needle (20). The applicator (10) includes a shroud (44) which cooperates with a trigger (41) and trigger lock (52) so that the needle (20) is only exposed upon actuation of the trigger (41) and liquid is only injected when the shroud (44) is retracted to a position at which a desired length of the needle (20) has penetrated.

Abstract: A disposable medicine delivery unit for use in a needleless hypodermic injector is configured to allow economical replacement, after each injection, of a patient contact surface and the entire injection flow-path of the medicament, to thereby ensure sterility with less need for repeated equipment cleaning and sterilization procedures. The delivery unit includes a piston seal configured to prevent improper reuse. The piston seal deforms and sticks in a conical end of the medicine delivery chamber at the end of its injection stroke. A push-only connection between the piston seal and a piston drive rod of the injector ensures that the latter cannot be used to retract the former. Preferably, the piston seal also includes a protruding nipple which enters and destroys the injection orifice following an injection, to further disable the delivery unit.

Abstract: A needleless injection system and method for injecting a medical product comprises a needleless injection device having a nozzle assembly defining an ampule chamber for holding medication, an energy device for pushing medication out of the nozzle assembly, and an energy device actuating mechanism. These components are operatively contained in a housing configured for a hand held operation. The energy device is a self-contained gas spring operatively connected to a plunger operating within the ampule chamber. The gas spring is preferably stepped which can be used in many different applications, an air gun being one. The injection device can be provide with a coupling device for coupling a medication supply vial to the nozzle assembly. The nozzle assembly is removably situated in the housing with the plunger removable therewith.

Abstract: An instrument for providing high pressure fluid pulses for cutting tissue including an internal pressure intensifying mechanism, and the provision of a suction force at the distal end of the instrument including an internal vacuum generating device to increase the suction force provided by a conventional suction source. A piston mechanism is provided for converting a low pressure fluid input to a high pressure fluid output, and a second piston mechanism is provided to intensify the suction force created by a conventional suction source at the surgical site.

Abstract: An apparatus for a controlled delivery of a liquid preparation from a cylindrical liquid container, which has a liquid outlet at its front end and a movable wall, which acts like a piston at its rear end is provided. The driving force acting on the movable wall for expelling the liquid from the container is generated by means of a piston rod in connection with a piston, which by the action of the atmospheric pressure is urged into a space where a vacuum has been established. The amount delivered can be varied according to different modes by providing an auxiliary force which acts on the piston during the initial stage of its movement into the vacuum space.

Abstract: The present invention relates particularly to a liquid infusion apparatus useful for infusing a medicinal liquid into a human or animal body.

Abstract: PCA apparatus has a container with a movable piston dividing the container into a lower chamber for medication liquid and an upper, air-filled chamber. A manually-actuated air pump is connected to the upper chamber so that air can be supplied to the upper chamber to displace the piston and discharge the liquid through a catheter. The air pump has a cylinder containing a plunger with a capillary inlet, to limit the rate at which air can flow into the cylinder and hence be pumped to the upper chamber. The lower chamber is filled through a removable inlet spike connector by pulling up the piston with an actuating rod projecting from the upper end of the container. The rod is frangible so that it can be removed after filling the lower chamber.

Abstract: An apparatus for controlled delivery of a liquid consists of a delivery unit which comprises a liquid container (3) having at least one movable wall (12) and a liquid outlet which is provided with a flow restriction, and a power unit which comprises a second container (21) which also has at least one movable wall (29) and wherein a vacuum may be established, and a mechanical coupling (31) between the movable wall (12) of the liquid container(3) and the movable wall (29) of the second container (21). The delivery unit and the power unit are connected together coaxially when the apparatus is prepared for delivery, and in this connecting together, the movable wall (29) of the second container is displaced by means of the mechanical coupling (31) such that the vacuum is established.

Abstract: A needleless, low pressure, air powered medicine injector with a quick disconnect medicine delivery assembly removably connected to the injector housing. Low pressure air drives a biased piston through a discharge stroke, beginning from the retracted position into the medicine chamber, thereby forcing medicine through a one-piece nozzle. A removable chamber filling mechanism connected to the housing is coupled to the medicine chamber through fill ports, such that the medicine chamber is filled utilizing a positive pressure medicine distributor. A movable spacer collar positioned in front of the nozzle provides an air gap between a patient's skin and the one-piece nozzle. A safety interlock coupled to an activating mechanism and the chamber filling mechanism prevents unwanted discharge of the injection.

Abstract: A device for controllably dispensing a liquid or viscous material comprises a chamber which is subdivided by a piston into a pressurized gas chamber and a mass chamber. The container includes electrochemical, tablet-shaped, completely enclosed diffusion electrodes, aqueous electrolytes, a gas development cell containing a counter-electrode, an adjusting rheostat and contacts held by a clamping device in the bottom of the container. A vibration-dampening funnel-shaped container cap encloses the top end of the container and is totally compliant and shock-proof. The piston includes a piston seal which has a sealing lip monolithically connected to the piston with a space for a film of grease. An alternative embodiment has exchangeable electric elements and a refilling device. Other alternative embodiments have a simplified compact design for small sizes or for infusion devices or are associated with piston sensors.

Abstract: An improved medication delivery device is a pen sized instrument that is powered by compressed inert gas. The needle-less injector device contains pre-filled and pre-measured medication dosages. The injector device has a pre-filled and self-contained compressed gas for providing pressure to inject the medication into the skin surface without the use of a needle. The injector device has a pressure sensitive deployment mechanism which insures proper seating of the injector face against the skin surface before medication delivery is accomplished. The needle-less injector device assures safe use by inexperienced operators (including children) under adverse conditions.

Abstract: Devices and methods are provided for surgical lavage including pumping liquid to a bone or other tissue surface with a reciprocating pump mechanism operated by pressurized gas wherein pressurized exhaust gas is further utilized to accelerate the pulsed liquid. A first valve arrangement is provided to bypass the pumping mechanism to direct pressurized gas directly onto the bone/other tissue surface without the presence of liquid from the device. A second valve arrangement is provided for optionally venting at least a portion of the exhaust gas to the atmosphere instead of directing it to the bone/other tissue surface. An additive line delivers additive to the gas bypass line for delivery of the additive to the bone/other tissue surface with the flowing gas stream.

Abstract: A portable infusion pump for infusing solutions from IV bags. The pump includes a housing having a compartment for removably receiving the bag in a solution-dispensing position. A push plate is mounted on the upper end of a flexible bladder having an outer wall which encloses a pressure chamber. The fluid is moved from a reservoir by a peristaltic pump into the pressure chamber so that the bladder is expanded to move the pressure plate toward the IV bag for dispensing the solution through IV tubing to the patient. The bladder has a predetermined configuration so that the differential volume required to fully dispense the solution from the IV bag is less than about 75% of the volume which is swept by movement of the push plate through its full stroke length. The IV tubing is connected to the IV bag by a filling spike having an annular groove which registers with a lock structure on the end of a lid. The lid is manually opened for insertion and removal of the bag to and from the housing compartment.

Abstract: Delivery devices which include a beneficial agent and an activating mechanism in separate compartments separated by a moveable partition are designed to deliver the beneficial agent in a pulsatile manner through an orifice. The pulsatile delivery is achieved by a band of resilient material which is placed over the orifice. The resilient material is sufficiently tight to substantially seal the orifice when the pressure within the device is below a threshold level while at the same time being capable of being stretched when the internal pressure exceeds the threshold.

Abstract: A dispensing device particularly useful for dispensing nutritional liquids includes an electrolytic cell having electrodes and an electrolyte capable of generating a gas upon the energization of the electrodes, which gas causes the dispensing of the liquid according to the rate of generation of the gas. The container for the liquid to be dispensed may be a disposable unit including the electrolytic cell, and a non-disposable electrical control circuit may be provided for controlling the rate of energization of the electrodes. The dispensing unit may also include an outer container adapted to receive a bag containing the liquid to be dispensed, the generated gas being applied between the outer container and the pliable bag.

Abstract: A needless injection device includes an initiator valve controlling flow of compressed gas into a reservoir. A poppet valve connecting to the reservoir has a gas pressure regulation end to regulate flow from the initiator valve into the reservoir. A clamp piston is driven forward by gas pressure from the reservoir and causes jaws to clamp onto a plunger extending into an ampule. The poppet valve opens when reservoir pressure reaches the cracking pressure of the poppet valve. Gas from the reservoir rushes through the popper valve into a drive chamber and forces a drive piston, containing the clamp piston and jaws, forward causing the plunger to slide into the ampule. A jet of injectant sprays out of the nozzle of the ampule and penetrates through the patient's skin.

Abstract: An animal vaccination gun for administering a vaccination to an animal has a movable needle assembly which is brought into engagement with a metering chamber having a spring-biased piston mounted therein during the injection of a medicament to an animal. During the injection, fluid is forced out of the metering chamber and through the needle assembly by the spring-biased piston. After the injection, fluid pressure forces the needle assembly out of engagement with the metering chamber and enables the metering chamber to be refilled.

Abstract: Providing fluid to an internal delivery site of a patient includes moving the fluid from a fluid reservoir through a conduit and through a delivery device at the delivery site while maintaining the fluid at a predetermined pressure. The delivery device may comprise an inflatable balloon with apertures formed in its periphery for directing the fluid into the vessel walls. Pressurized fluid is provided through the apertures of the balloon to the vessel wall. The pressure is automatically controlled to avoid both pressure spikes and unacceptable deflation of the balloon during administration of the fluid. A further feature includes comparing the pressure with the volume infused and in the event that pressure decreases while the volume infused increases beyond certain limits, the delivery of the fluid is stopped. Further features include a timer for limiting the inflation time of the delivery device and a volume detector for controlling the amount of fluid delivered.

Abstract: A method for injecting viscous material into the eye. In the injection into the eye, sufficient material is injected to separate a membrane from the retina so that intraocular scissors may be manipulated between the membrane and the retina to cut the attachment points. The membrane is then aspirated away. The injection is done using a standard glue injector with a one-shot and a continuous mode. The glue injector is pneumatically coupled through a sterile filter and a custom adaptor to a sterile syringe storing the material to be injected.

Abstract: Delivery devices which include a beneficial agent and an activating mechanism in separate compartments separated by a moveable partition are designed to deliver the beneficial agent in a pulsatile manner through an orifice. The pulsatile delivery is achieved by a band of resilient material which is placed over the orifice. The resilient material is sufficiently tight to substantially seal the orifice when the pressure within the device is below a threshold level while at the same time being capable of being stretched when the internal pressure exceeds the threshold.

Abstract: The present invention is directed to a syringe that includes a gas driven piston to force liquid medication from a syringe cartridge through a variety of injection nozzles. The syringe may be mechanically operated for loading or aspirating the syringe.

Abstract: An impact releasable pole mounted syringe is described which includes a pole member having a gripping end and a syringe attachment end. The syringe attachment end has a receptacle with an opening adapted to telescopically receive a syringe. The pole member has a flexible finger protruding past the syringe attachment end and biased radially away from the pole member. The finger has an engagement member positioned at a remote end. A syringe is provided having a plunger end and a needle end. The plunger end is adapted for telescopic insertion into the receptacle at the syringe attachment end of the pole member. The syringe has an annular collar serving as a stop to limit the telescopic insertion of the syringe into the receptacle. The syringe has an engagement channel adapted to receive the engagement member.

Abstract: A pneumatic powered, modular device, suitable for giving an adjustable dose of liquid medication to animals drawing the liquid from a bulk container. Modular design permits several ranges of dosage as well as methods of delivery such as hypodermic, oral or poured on skin. In FIG. 1 we show the hypodermic mode. Compressed air enters handle 1 at base through fitting 18, goes through passage 19 into 3 way valve 21 normally closed. Depressing trigger 22 allows air to enter chamber 24 pushing piston 7 forward. Liquid in front of piston 7 is expelled past check valve 25 into chamber 26 and out of hypodermic needle. Gasket 30 holds liquid in. For oral delivery, terminal 35 is substituted. Upon release of trigger 22, 3 way valve 21 permits air on chamber 24 to exhaust via exit 31 on valve, spring 11 pulls piston back until fitting expansion 13 stops against adjustable nut 6. This determines size of dosage.

Abstract: An intraruminal device for controlled release of a drug formulation in the rumen of an animal, comprises an open-ended tube for containing the drug formulation, a piston adapted to travel longitudinally within the tube and biased so as to deliver the drug formulation through the open end of the tube. Travelling with the piston is an associated weight adapted to retain the device within the rumen during delivery of the drug formulation.

Abstract: An apparatus for delivering fluid with a relatively constant, controlled rate of flow comprises a vacuum power means, a fluid storage means in axial alignment with the vacuum power means and a plunger means carried by the vacuum power means and in axial communication with the fluid storage means. The plunger means is driven by a vacuum which collapses under atmospheric pressure, and as it is driven it effects delivery of the fluid from the fluid storage means.

Abstract: An apparatus and method for injecting viscous material into the body. In the case of injection into the eye, sufficient material is injected to separate a membrane from the retina so that intraocular scissors may be manipulated between the membrane and the retina to cut the attachment points. The membrane is then aspirated away. The injection is done using a standard glue injector with a one-shot and a continuous mode. The glue injector is pneumatically coupled through a sterile filter and a custom adaptor to a sterile syringe storing the material to be injected.

Abstract: A needleless injection device has a housing containing a pilot valve connectable to a compressed gas source. A main valve is operatively connected to the pilot valve. The pilot valve and main valve form a two-stage valve with the pilot valve activatable to open the main valve utilizing gas pressure. Compressed gas in a reservoir flows through the open main valve to driven a plunger into an ampule to inject an injectant through a patient's skin.

Abstract: A device for dispensing a liquid, particularly a medicament, at a predetermined rate, includes a container including a displaceable partition to define a first expansible-contractible chamber on one side for receiving the liquid to be dispensed, and a second expansible-contractible chamber on the opposite side for receiving an electrolytic cell. The electrolytic cell has electrodes and an electrolyte capable of generating, upon the energization of the electrodes, a gas under pressure to thereby displace the displaceable partition and to force the liquid out from the first chamber in accordance with the rate of energization of the electrodes. The displaceable partition includes a piston assembly having a pair of pistons spaced apart by a connecting stem, the container being formed with a vent opening in the space between the pistons to prevent accidental mixing of the gas with the liquid to be dispensed.

Abstract: The invention concerns a device and a process for administering a liquid g preparation, in particular by infusion, by implantation or percutaneously, at a given flow rate for relatively long period of time, using a technique involving the retractation of an elastic membrane. More specifically, using this technique, said drug preparation is placed in a tubular reservoir (13) where it is subjected to the action of at least one movable wall (112, 112a). The movable wall is displaced by the pressure of a hydraulic fluid (10), the entry of which is controlled by a capillary tube (4) fed with hydraulic fluid (10) under pressure by a hydraulic accumulator subject to the thrust of a previously dilated retractable elastic membrane (8).

Abstract: A vacuum biased disposable infuser is provided having a liquid chamber (14) and at least one vacuum chamber (44). The liquid chamber (14) includes a liquid plunger (26) contained therein while the vacuum chamber (44) includes a vacuum plunger (48). The plungers (26, 48) are connected by an arm such that when liquid under pressure is provided to the liquid chamber (14), the vacuum plunger (48) is drawn back in the vacuum chamber (44). The device is further preloaded such that at the end of infusion, the vacuum plunger (48) does not abut against the vacuum chamber (44).

Abstract: A pneumatic retinopexy injector includes a syringe to which is communicated a controllable gaseous pressure source. A desired volume of a gaseous substance can be injected by the syringe by utilizing a controller to introduce the pressurized gas to the syringe to cause the piston of the syringe to eject any contents of the syringe. The manual controller can comprise a foot pedal having a variable flow pneumatic valve. The invention can also utilize a vacuum source which is switchable to the syringe to allow automatic filling of the syringe.

Abstract: A device for injecting serum or the like into animals while remaining at a distance from the animal. The device uses air pressure from a tank built into the device to eject the serum from a syringe on the tip of the wand. The wand is long enough to provide relative safety for the user.

Abstract: A device to introduce a liquid into the hypoderma, the device includes a reservoir which receives a gas under pressure, the gas is delivered via a valve to an interacting piston and cylinder. When the gas is delivered to the piston, the piston moves to eject a liquid from a capsule mounted within the device. The liquid contained in the capsule is then ejected through a nozzle located against the skin of the user.

Abstract: An insert head (102) is tightly inserted in the rearward end of a commercially available ampoule (101) equipped with a plunger (100). A galvanic, gas-generating cell is arranged in the insert head (102). The plunger (100) is driven forward by the gas generated by this cell. A throttle device (103) constituted by a capillary tube is connected to the Luer's syringe (109) of the ampoule (101), the infusion fluid driven out by the plunger (100) flowing through this throttle means into a catheter (104).

Abstract: Inert or biologically active particles are propelled at cells at a speed whereby the particles penetrate the surface of the cells and become incorporated into the interior of the cells. The process can be used to mark cells or tissue or to biochemically affect tissues or tissue in situ as well as single cells in vitro. Apparatus for propelling the particles toward target cells or tissues are also disclosed. A method for releasing particles adhered to a rotor device is also disclosed.

Abstract: A hand-held and operated pneumatically powered device for injecting fluids, such as in medical applications, consisting of a housing that is sized and shaped to be hand held, and connected power and infusion assemblies contained within the housing. The power assembly includes a sealed vessel containing pressurized gas, a lever-needle vessel-puncturing mechanism, a gas flow path leading from the needle to the infusion assembly, and pressure regulator and pressure relief mechanism (which may include a pneumatic flow control orifice) interposed in the flow path.

Abstract: A pre-filled ampule and a powered, non-invasive injection device assembly wherein the device includes a housing having an ampule-receiving chamber, a gas charge, and means for delivering a predetermined amount of gas to an ampule-receiving chamber. The device includes an injection-counting ring which is received in a groove extending about the housing wherein the ring includes a counting mechanism thereon and is constructed to allow one-way only rotation thereof relative to the housing. The ampule includes an elongate ampule body having a medication holder located at one end thereof, a transfer area located adjacent the other end thereof and a bypass area located adjacent an end of the transfer area. A plunger is provided and has one end thereof received in and closing one end of the medication holder with the other end of the plunger being received in the ampule-receiving chamber of the injection device. A floating seal is received and encloses the other end of the medication holder.

Abstract: The assembly includes an injection device which includes a housing having an ampule-receiving chamber, a gas charge, and means for delivering a predetermined amount of gas to the ampule-receiving chamber. The device includes an injection-counting ring which is received in a groove extending about the housing wherein the ring includes a counting mechanism thereon and is constructed to allow one-way only rotation thereof relative to the housing. The patient-fillable ampule of the invention includes an ampule body having a plunger end and an orifice end, a medication retaining cavity and an elongate plunger which is received in one end of the cavity. An orifice-bearing end cap is fixed to the orifice end of the body. A truncated hypodermic needle is received in the end cap. A removable needle is provided for filling the ampule and allows use of the ampule as a conventional syringe.

Abstract: Disposal apparatus for the safe disposal of a medicinal needle after use utilizing a container with a vacuum therein and a piston attached to one side of the needle which protrudes ready for use. After use of the needle, one side of the piston is exposed to ambient pressure and the needle is retracted into the container for safe disposal. A sight chamber attached to said piston within said container and communicating with said needle indicates when said needle has pierced a blood vessel. In another embodiment, a spring is employed to retract the needle.

Abstract: A non-invasive hypodermic injection device includes a two-stage gas delivery system and a medication containing ampule having a truncated hypodermic needle at one end thereof. An ampule shroud encloses the ampule and maintains separation between the truncated hypodermic needle on the ampule and the skin of a patient being injected.

Abstract: An infusion device for dispensing drugs and other fluids at controlled rates over extended time periods. The device includes a syringe section and a power section that are connected together in use, the power section having a casing defining a first chamber containing a vacuum-stable viscous liquid and a second chamber under partial vacuum. A metering passage extends between the two chambers, and a piston is slidably received in the casing and constitutes a movable wall of the first chamber so that as the viscous liquid gradually flows through the metering passage into the second chamber the piston retracts slowly to cause fluid to be discharged from the syringe.

Abstract: The infusion pump delivers liquid to a body at an adjustably controlled rate of delivery. The pump comprises a syringe section including a syringe barrel having a nozzle at one end. A syringe piston has an inner end situated in the syringe barrel and an outer end extending out of the other end of the syringe barrel. A drive mechanism comprising a generally cylindrical housing has one end mounted to the other end of the syringe barrel. The outer end of the piston extends into the one end of the housing. A gas spring is situated at the other end of the housing and a dampening/timing mechanism is positioned between the gas spring and the outer end of the syringe piston. The dampening/timing mechanism includes a viscous fluid which is movable through a passageway in the housing from a space adjacent the gas spring to a space above the piston. A control mechanism is provided for altering the flow rate of the viscous fluid through the passageway and between the spaces.