Pistol-type syringe

Abstract

Disclosed is a pistol-type syringe for injecting the contents of an ampoule or the like by means of an axial displaceable piston. The syringe includes a handle member with a generally flat frontal surface having a bore through which an axially displaceable plunger member is positioned. The ampoule or the like is held in a position coaxial with the plunger. The plunger is provided with a generally disk-shaped pressure piece which is slidable along the plunger and which has a rest position defined by the flat frontal surface of the handle member. The handle member also has an associated activating lever which is operable to exert a force on the pressure piece.

I claim: 
     
       1. A pistol-type syringe for injecting the contents of an ampoule having therein a piston which discharges the contents upon axial displacement, said syringe comprising: a handle member having an upper portion with a first generally flat frontal surface and having an axial bore extending therethrough;   an elongated plunger member longitudinally displaceably positioned in the bore;   means, associated with the upper portion of said handle member, for holding an ampoule in a position forward of said handle member and substantially coaxial with said plunger;   a generally disk-shaped first pressure piece having an aperture therein which is slightly larger than the outer circumference of said plunger member, said first pressure piece being slidably positioned on said plunger member and having a rest position defined by said first surface of said upper portion of said handle member, said rest position being generally perpendicular to the axis of said bore; and   an actuating lever pivotably mounted on said handle, the upper end of said lever being adapted upon pivoting of said lever to exert a force on said pressure piece in a direction generally parallel to said plunger member and at a position on said first pressure piece spaced radially outwardly from said plunger member.   
     
     
       2. A syringe according to claim 1, wherein said ampoule holding means comprises a tubular guide piece connected to said handle member, said guide piece having radially opposing longitudinal extensions extending in the forward direction, a generally tubular ampoule holder pivotably mounted on said extension for rotation into and out of coaxial alignment with said guide piece, a third pressure piece having an aperture therein larger than the circumference of said plunger member, said third pressure piece being slidably positioned inside of said guide piece and having a front portion which has an outer dimension equal to the inner dimension of said ampoule holder, means for normally spring biasing said third pressure piece forwardly so that said front portion extends into said ampoule holder, and means for selectively withdrawing said front portion from said ampoule holder so that said ampoule holder can be rotated for insertion and removal of an ampoule from the rear. 
     
     
       3. A pistol type-syringe for injecting the contents of an ampoule having therein a piston which discharges the contents upon axial displacement, said syringe comprising: a handle member having at its upper portion a bore extending therethrough;   an elongated plunger member longitudinally displaceably positioned in the bore;   ampoule holding means, associated with the upper portion of said handle member for holding an ampoule in a position forward of said handle member and substantially coaxial with said plunger;   said ampoule holding means comprising a tubular guide piece connected to said handle member, said guide piece having radially opposing longitudinal extensions extending in the forward direction, a generally tubular ampoule holder pivotably mounted on said extension for rotation into and out of coaxial alignment with said guide piece, a third pressure piece having an aperture therein larger than the circumference of said plunger member, said third pressure piece being slidably positioned inside of said guide piece and having a front portion which has an outer dimension equal to the inner dimension of said ampoule holder, means for normally spring biasing said third pressure piece forwardly so that said front portion extends into said ampoule holder, and means for selectively withdrawing said front portion from said ampoule holder so that said ampoule holder can be rotated for insertion and removal of an ampoule from the rear;   a generally disk-shaped first pressure piece having an aperture therein which is slightly larger than the outer circumference of said plunger member, said first pressure piece being slideably positioned on said plunger member; and   an actuating lever pivotingly mounted on said handle, the upper end of said lever being adapted upon pivoting of said lever to exert a force on said pressure piece in a direction generally parallel to said plunger member and at a position on said first pressure piece spaced radially outwardly from said plunger member.   
     
     
       4. A syringe according to claim 1 or 3, wherein said plunger member comprises a generally cylindrical, smooth rod and wherein said pressure piece comprises a circular disk with a center bore. 
     
     
       5. A syringe according to claim 1 or 3, further comprising a spring for biasing said pressure piece against said handle member. 
     
     
       6. A syringe according to claim 1 or 3, wherein said upper portion of said handle member includes a head piece containing the bore, said head piece having said first frontal surface and a slit on its side facing said handle member, wherein the upper end of said actuating lever projects forward from the slit in the head piece, wherein said pressure piece is arranged in front of the forward frontal surface of said head piece and wherein said spring comprises a helical compression spring positioned between said pressure piece and the rear end of said ampoule holding means, said spring surrounding said plunger member. 
     
     
       7. A syringe according to claim 6, wherein the upper end of said actuating lever comprises a spherically rounded head pointing in the forward direction for engaging with said pressure piece. 
     
     
       8. A syringe according to claim 6, further comprising means for braking rearward motion of said plunger member. 
     
     
       9. A syringe according to claim 6, wherein said braking means comprises a second generally disk-shaped pressure piece having an aperture therein which is slightly larger than the outer circumference of said plunger member, said second pressure piece being slidably positioned on said plunger member, and stop means positioned on said handle member for engaging the peripheral area of said second pressure piece and stopping rearward movement thereof. 
     
     
       10. A syringe according to claim 9, wherein said handle member includes a second generally flat surface facing to the rear opposite to said first frontal surface and being generally perpendicular to the axis of said bore and wherein said second pressure piece is located proximate to said second surface of said head piece and wherein said stop means projects upwardly from said handle member. 
     
     
       11. A syringe according to claim 9, wherein said braking means further comprises means for biasing said second pressure piece in the rearward direction at its periphery radially opposite said stop means. 
     
     
       12. A syringe according to claim 1 or 3, wherein said ampoule holding means includes at least one window, and further comprising a transparent intermediate tube member positioned in said ampoule holding means. 
     
     
       13. A syringe according to claim 1 or 3, wherein said withdrawing means comprises an enlarged forward end portion on said plunger member having an outer dimension larger than the aperture in said third pressure piece and a grasping portion at the opposite end of said plunger member. .Iadd. 
     
     
       14.  A syringe for injecting the contents of an ampoule having therein a piston which discharges the ampoule contents upon axial displacement, said syringe comprising: means for holding an ampoule;   a plunger longitudinally displaceable along a path extending through said ampoule holding means;   said holding means including at least one window through which an ampoule in said holding means may be observed; and   a transparent intermediate member positioned in said ampoule holding means so as to be located between said window and an ampoule disposed therein, wherein said transparent intermediate member is a tube positioned in said ampoule holding means to surround an ampoule disposed therein. .Iaddend. .Iadd.15. A syringe according to claim 14, wherein said ampoule holding means comprises a tubular sleeve and said window comprises an opening through the wall of said sleeve. .Iaddend. .Iadd.16. A syringe according to claim 14, wherein said transparent intermediate member extends along the entire length of said ampoule holding means. .Iaddend. .Iadd.17. A syringe according to claim 14, wherein said tube is secured in said ampoule holding means by a removable cap attached to the forward end of   
     
     
        said ampoule holding means. .Iaddend. .Iadd.18.  A syringe according to claim 17, wherein said tube is loosely displaceable and rotatable within said ampoule holding means. .Iaddend. .Iadd.19. A syringe according to claim 14, wherein said transparent intermediate member is formed of acrylic material. .Iaddend. .Iadd.20. A syringe according to claim 14, further comprising guide means for guiding said plunger along said path through said ampoule holding means. .Iaddend. .Iadd.21. A syringe according to claim 14, wherein said transparent intermediate member is removable from said ampoule holding means. .Iaddend.