Fluid dispensing arrangement

For use in an arrangement adapted to have a dispensable liquid therein and which utilizes a manually operated plunger for dispensing liquids, the improvement comprising:

• a liquid-carrying body having at its forward end a mouth, a central liquid-holding chamber, and an opposite open end for receiving said plunger to effect movment of liquid to or from said chamber and through said mouth,
• a combination sealing and by-pass valve plug having a radially compressible, relatively soft elastic midsection initially seated within and sealing said mouth in a radially elastically compressed condition of the plug,
• a by-pass chamber and associated connected fluid discharge opening formed forward of said mouth, said by-pass chamber being larger in internal cross-section than said mouth and larger in all directions of cross-sectional chamber extent than the respective corresponding elastically free released external configuration of said plug whereby said plug will have freedom of movement in all lateral directions when effectively fully ejected into said chamber from its sealing condition in said mouth,
• the opposite ends of said plug being non-complementarily shaped relative to the opposite longitudinal ends of said by-pass chamber, so as to enable liquid to pass therepast when the plug is in end engagement with either the forward or rear end of said by-pass chamber, after removal of the plug from its sealing position within said mouth and into said by-pass chamber,
• said plug being of a normal cross-section in its elastically free released condition sufficiently greater than said mouth of said body to prevent, in conjunction with one of its said non-complementarily shaped ends, reverse movement thereof back into sealing relation within said mouth as a function of reverse or aspirating flow of liquid therepast.

For use in an arrangement adapted to have a dispensable liquid therein and which utilizes a manually operated plunger for dispensing liquids, the improvement comprising:

• a body having a liquid-holding chamber with a forward mouth, said chamber including a section for movement of said plunger therealong to effect movement of liquid to or from said chamber and through said mouth,
• a combination sealing and by-pass valve plug having a radially compressible, relatively soft elastic midsection initially seated within and sealing said mouth in a radially elastically compressed condition of the plug,
• a by-pass chamber formed forward of said mouth and larger in internal cross-section than said mouth and larger in cross-sectional chamber extent than the respective corresponding elastically free released external configuration of said plug,
• the opposite ends of said plug being non-complementarily shaped relative to the opposite longitudinal ends of said by-pass chamber, so as to enable liquid to pass therepast when the plug is in end engagement with either the forward or rear end of said by-pass chamber, after removal of the plug from its sealing position within said mouth and into said by-pass chamber,
• said plug being of a normal cross-section in its elastically free released condition sufficiently greater than said mouth of said body to prevent, in conjunction with one of its said non-complementarily shaped ends, reverse movement thereof back into sealing relation within said mouth as a function of reverse or aspirating flow of liquid therepast.

For use in an arrangement adapted to have a dispensable liquid therein and which utilizes a manually operated plunger for dispensing liquids, the improvement comprising:

• a liquid-carrying body having at its forward end a mouth, a central liquid-holding chamber, and an opposite open end for receiving a plunger to effect movement of liquid to or from said chamber and through said mouth,
• a combination sealing and by-pass valve plug having a radially compressible, relatively soft elastic midsection initially seated within and sealing said mouth in a radially elastically compressed condition of the plug,
• a by-pass chamber and associated connected liquid discharge opening formed forward of said mouth, said by-pass chamber being larger in internal cross-section than said mouth and the elastically expanded cross-section of said plug,
• the opposite ends of said plug being non-complementarily shaped relative to the opposite longitudinal ends of said by-pass chamber, so as to enable liquid to pass therepast when the plug is in end engagement with either the forward or rear end of said by-pass chamber, after removal of the plug from its sealing position within said mouth and into said by-pass chamber,
• said plug being of a normal cross-section in its elastically free released condition sufficiently greater than said mouth of said body to prevent reverse movement thereof back into sealing relation within said mouth as a function of reverse or aspirating flow of the liquid therepast,
• the rear zone of said plug being elastic and having a tapered external surface smaller at its rear extremity than at the forward end of such tapered surface, a portion of said tapered rear surface being larger in elastically free released condition than the effective forward exit end zone of said mouth, whereby said plug is aided in passage forward through the forward exit end of said mouth by the combined action of the compressive forces within the laterally compressed plug and acting to restore the plug to an unstressed released state and the camming surface interaction between the tapered external surface of said plug and the forward end of said mouth, said tapered external surface aiding in preventing sealing, re-entry and sealing seating of said plug into said mouth as a result of aspirating liquid flow action on said plug.

An arrangement for dispensing liquid comprising:

• a syringe body having a substantially constant diameter bore forming a liquid-holding chamber, said bore chamber being adapted for movement of a plunger therealong,
• a plunger slidably movable in said bore chamber to effect movement of liquid to or from said chamber and through said mouth,
• a combination sealing and by-pass valve plug having a radially compressible, relatively soft elastic midsection initially seated within and sealing said mouth in a radially elastically compressed condition of the plug,
• a step-enlargement annular by-pass chamber formed forward of said mouth and larger in internal cross-section than said mouth and the elastically expanded cross-section of said plug, and having a liquid discharge opening adjacent its forward end zone,
• the opposite ends of said plug being non-complementarily shaped relative to the opposite longitudinal ends of said by-pass chamber, so as to enable liquid to pass therepast when the plug is in end engagement with either the forward or rear end of said by-pass chamber, after removal of the plug from its sealing position within said mouth and into said by-pass chamber,
• said plug being of a normal cross-section in its elastically free released condition greater than said mouth of said body to prevent, in conjunction with one of its non-complementarily shaped ends, reverse movement thereof back into sealing relation within said mouth as a function of reverse or aspirating flow of liquid therepast,
• the rear zone of said plug being elastic and having a tapered external surface smaller at its rear extremity than at the forward end of such tapered surface and smaller than at the forward end of the cross-sectional configuration of said mouth, a portion of said tapered rear surface being larger in elastically free released condition than the effective forward exit end zone of said mouth, whereby said plug is aided in passage forward through the forward exit end of said mouth by the combined action of the compressive forces within the laterally compressed plug and acting to restore the plug to an unstressed released state and the camming surface interaction between the tapered external surface of said plug and the forward end of said mouth, said tapered external surface aiding in preventing sealing re-entry and sealing seating of said plug into said mouth as a result of aspirating liquid flow action on said plug.