Hand powered hypodermic jet injector gun

Claim 2

In a hydraulic powered jet injector instrument of the type having a housing with a hydraulic chamber, a hydraulic piston reciprocally mounted in said hydraulic chamber and rigidly connected to a medicament piston and wherein a spring means biases said hydraulic piston in one direction in said hydraulic chamber, the improvement comprising: a muzzle slidably mounted at one end thereof to said housing, and extending partially within said hydraulic chamber, the second end of said muzzle surrounding said medicament piston, said one end of said muzzle extending sufficiently into said hydraulic chamber to act as a stop for said hydraulic piston, a nozzle means on the other end of said muzzle for ejecting said medicament: said nozzle means, said muzzle and said medicament piston defining a medicament chamber, and an adjustable coupling means operatively coupling said muzzle and said housing for adjusting the volume discharged from said medicament chamber.

Claim 3

In a hydraulic powered jet injector instrument as defined in claim 1, wherein said adjustable coupling means comprising a rotatable ring threadedly engaged on said housing and having an internal first radial flange, said muzzle having an external second radial flange engageable by said first radial flange, whereby the axial position of said muzzle with respect to said housing is determined by the rotational position of said ring.

Claim 4

A hand powered jet injector instrument comprising: a hollow housing; a handle depending from said housing, said handle being formed with a cavity for containing a fluid, said housing being formed with a first chamber communicating with said cavity for receiving said fluid therefrom; a hand operated pump on said housing arranged to pump said fluid from said cavity into said chamber; a piston movable axially in said chamber and retracted by fluid pumped into said chamber; a coil spring in said chamber adapted to be compressed by said piston when said piston is retracted in said chamber; a muzzle slidably mounted at one end thereof to said housing, and extending partially within said chamber, said one end of said muzzle extending sufficiently into said chamber to act as a stop for said piston; a piston rod attached to said piston and axially slidable in said muzzle; a nozzle means at the other end of said muzzle for ejecting a jet of a medicament, said nozzle means piston rod and said muzzle defining a second chamber for containing said medicament; and adjustable coupling means operatively coupling said muzzle and said housing and for adjusting the volume discharged from said second chamber.

Claim 5

A hand powered jet injector instrument comprising: a hollow housing; a handle depending from said housing, said handle being formed with a cavity for containing a fluid, said housing being formed with a first chamber communicating with said cavity for receiving said fluid therefrom; a hand operated pump on said housing arranged to pump said fluid from said cavity into said chamber; a piston movable axially in said chamber and retracted by fluid pumped into said chamber; a coil spring in said chamber adapted to be compressed by said piston when said piston is retracted in said chamber; a muzzle slidably mounted at one end thereof to said housing, and extending partially within said chamber, said one end of said muzzle extending sufficiently into said chamber to act as a stop for said piston; a piston rod attached to said piston and axially slidable in said muzzle; a nozzle means at the other end of said muzzle for ejecting a jet of a medicament, said nozzle means piston rod and said muzzle defining a second chamber for containing said medicament; and adjustable coupling means operatively coupling said muzzle and said housing and for adjusting the volume discharged from said second chamber.

Claim 6

A hand powered jet injector instrument as defined in claim 3, further comprising a manually operable trigger carried by said housing; and one-way valve means operated by said trigger, said valve means controlling return of fluid from said first chamber to said cavity to permit said spring to expand and move said piston and said piston rod axially to eject said medicament from said chamber.

Claim 7

A hand powered jet injector instrument as defined in claim 3, further comprising: a container of medicament; a support means for holding said container onto said muzzle; said support means including a passage communicating with said second chamber for passing said medicament from said container into said second chamber.

Claim 8

A hand powered jet injector instrument as defined in claim 5 further comprising: a manually operable trigger carried by said housing; and one-way valve means operated by said trigger said valve means controlling return of fluid from said first chamber to said cavity to permit said spring to expand and move said piston and said piston rod axially to eject said medicament from said second chamber.

Claim 9

A hand powered jet injector instrument as defined in claim 3, wherein said adjustable coupling means comprising: a rotatable ring threadedly engaged on said housing and having an internal first radial flange; said muzzle having an external second radial flange engageable by said first radial flange, whereby the axial position of said muzzle with respect to said housing is determined by the rotational position of said ring.

Claim 10

A hand powered jet injector instrument as defined in claim 7, further comprising: a containeR of medicament; a support means for holding said container onto said muzzle; said support means including a passage communicating with said second chamber for passing said medicament from said container into said second chamber.

Claim 11

A hand powered jet injector instrument as defined in claim 8 wherein said support means further comprises: a bar having a saddle at one end engaged with said muzzle; and guide means on said housing engageable with the other end of said bar for preventing said muzzle from rotating with respect to said housing.

Claim 12

A hand powered jet injector instrument as defined in claim 9 wherein said saddle includes a fitting engaged in said saddle and having a passage communicating with said second chamber for passing said medicament from said container into said second chamber.

Claim 13

A hand powered jet injector instrument as defined in claim 9, further comprising a bracket on said bar adjustably engaging said container to hold the same in place while passing said medicament into said second chamber.

Claim 14

A hand powered jet injector instrument as defined in claim 11, furthr comprising a manually operable trigger carried by said housing; and one-way valve means operated by said trigger, said valve means controlling return of fluid from said first chamber to said cavity to permit said spring to expend and move said piston and said piston rod axially to eject said medicament from said second chamber.

Claim 15

A hand powered jet injector instrument as defined in claim 12, further comprising other one-way valve means in said handle and said housing arranged to permit passage of said fluid from said cavity to said first chamber when said pump is operated, said pump comprising a further passage formed in said housing and a pump rod axially slidable in said further passage, said further passage extending between said first chamber under control of said other one-way valve means.