Dispenser

Claim 2

A dispenser device for dispensing predetermined successive quantities of fluid through a needle which comprises an elongated body adapted for placement of a double-pointed hollow needle at one end thereof; said elongated body further comprising separable top and bottom longitudinal sections secured together, the bottom section having a reservoir region adapted to contain therein a prefilled reservoir to serve as fluid reservoir for dispensing the fluid therefrom; a needle placement locale on the bottom section whereby a double-pointed hollow needle situated thereon would extend into the region for the prefilled reservoir and into the fluid of any reservoir in said region; the top section containing the dispensing mechanism of: a non-rotatable pressure responsive means element adapted to be pushed longitudinally inward from outside of said body, advancing same longitudinally in said body; a stationary rotatable screw operatively connected to said pressure responsive means element and rotated by advancing movement of said element; a stationary rotatable piston rod nut operatively connected to said rotatable screw and rotated by said rotatable screw and a non-rotatable piston rod threaded to said piston rod nut and advanced by rotation of said piston rod nut; spring means adapted to cause said pressure responsive means element to retract when pushing pressure thereon ceases; and means adjacent the connection between said screw and said piston rod nut for preventing reverse rotation of said screw during retraction movement of said element; said piston rod extending into the region for the prefilled reservoir whereby advancing movement of said piston rod could expel fluid from a reservoir in said region.

Claim 3

The dispenser device of claim 1 containing therein a reservoir that comprises a prefilled sealed cartridge in the form of a liquid filled tube having a septum at one end, said septum being pierceable by a double-pointed hollow needle and a slidable plug in the tube at the other end; said reservoir being insertable only when the top and bottom sections are separated, assembly of said top and bottom sections with a prefilled reservoir therein generating contact of the piston rod with said plug, whereby advance of said piston rod will force said plug forward and expel fluid from said cartridge.

Claim 4

The dispenser device of claim 2 further including a needle assembly mounted on the elongated body, said needle assembly further comprising a double-pointed hollow needle, an internally threaded cup through the base of which said needle extends, and wherein said needle is firmly secured, the needle end of said elongated body being externally threaded, whereby said needle assembly is removably secured on to said body, and optionally, a removable housing around the needle protecting same, assembly of said top and bottom sections generating also sufficient piston rod induced forward movement of said plug to expel fluid into said needle displacing air therefrom.

Claim 5

The dispenser device of claim 1 further comprising a pressure responsive means element located essentially flush to the top end of said elongated body, depressable longitudinally inside the elongated body for causing the advancement of said piston rod.

Claim 6

The dispenser device of claim 4 further comprising a multipurpose cap member, said cap member being adapted for placement on the needle end of said elongated body so as to be protective of any needle thereon, and, alternatively, on the top end of said body at which location said cap member is superposed on the pressure responsive means element and constitutes a longitudinal extension thereof; an applicator on said cap adapted to be pressed by a user's finger then being in bearing contact with said pressure responsive means element, whereby finger pressure on said applicator causes the applicator to push against said pressure responsive means element advancing said element for causing the advancement of said piston rod as aforesaid.

Claim 7

The dispenser device of claim 1 wherein the stationary rotatable piston rod nut comprises a tubular member a portion of which is split into a multitude of biased-apart and internally threaded legs, the piston rod having thereon external threads corresponding to the aforementioned threads on the legs of said piston rod nut, the stationary rotatable piston rod being located inside the piston rod nut, freely movable relative to the piston rod nut when the two body sections are separated, and means in said elongated body section that clamp the internally threaded legs of said piston rod nut to the externally threaded piston rod when the two body sections are joined to form said elongated body, so that the piston rod advances when the piston rod nut rotates, the piston rod being retractable when the body sections are separated.

Claim 8

The dispenser device of claim 6 wherein the means for clamping the internally threaded legs of said piston rod nut to said piston rod comprises a guide through which the piston rod extends adapted to prevent rotation of the piston rod, said guide being movable between a clamping location when the two body sections are joined, and a non-clamping location when the two body sections are separated.

Claim 9

The dispenser device of claim 7 wherein said movable guide is adapted to be moved from non-clamping location to clamping location by the end of a prefilled reservoir when such is present in said elongated body.

Claim 10

The dispenser device of claim 1 wherein the means for preventing reverse rotation of said screw is a unidirectional transmission system comprising: a first lock disc associated with said pressure responsive means element during advancement and retraction longitudinal movement, the association including a pawl system set to secure said element and first lock disc against relative rotation during advancing movement of said element and lock disc, to allow rotation of said first lock disc upon retraction movement; said screw extending through said first lock disc so as to require rotation by said screw upon advance of said element during which said first lock disc advances along the shank of said screw, said first lock disc thereby being caused to rotate during retraction movement along the shank of said screw; a second and stationary lock disc associated with said screw and said piston rod nut adjacent the connection between said screw and said piston rod nut, through which said screw extends to a driving connection with said piston rod nut, said second lock disc and said piston rod nut being associated by a pawl system set to allow rotation of the screw during advancement of said pressure responsive means element thereby rotating said piston rod nut, and to secure said piston rod nut against reverse rotation, whereby upon retraction movement of said pressure element during which said first lock disc retracts along the shank of said screw, the pawl system of said second lock disc prevents rotation of said piston rod nut and thereby of said screw, forcing the rotation of said first lock disc as aforesaid, the aforesaid spring means maintaining said first and second lock discs in their pawl system association contact with said element and piston rod nut respectively.

Claim 11

The dispenser device of claim 9 wherein the pawl system associated with said second lock disc and piston rod nut is adapted to generate an audible sound upon rotation of said piston rod nut, whereby the user of the dispenser device may be made aware when fluid is being dispensed therefrom.