Needleless hypodermic injection device

Claim 2

An injection device comprising: a housing; a plunger driver slidably disposed within said housing; a pilot valve within said housing connectable to a compressed gas source; and a main valve having a substantially unbiased main valve piston, said main valve operatively connected to said pilot valve, said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive said plunger driver.

Claim 3

The injection device of claim 1 further comprising: a cartridge holder attachable to said housing and having a cartridge chamber; a valve body disposed within said housing; and a gas delivery tube connecting said cartridge chamber and said valve body.

Claim 4

The injection device of claim 2 further comprising a piercing body spaced apart from said valve body and forming a reservoir therebetween.

Claim 5

The injection device of claim 2 further comprising a gas filter associated with said gas delivery tube.

Claim 6

The injection device of claim 2 further comprising at least one bleed hole in said gas delivery tube.

Claim 7

The injection device of claim 1 further comprising a liner having a liner seat, and a main valve piston with said main valve piston and said liner seat comprising said main valve.

Claim 8

The injection device of claim 3 wherein at least said liner and said main valve piston form an annular chamber between said liner and said main valve piston with said annular chamber connected by at least one gas passageway to said reservoir.

Claim 9

The injection device of claim 7 wherein said gas passageway comprises a slot on said valve body.

Claim 10

The injection device of claim 6 wherein said main valve piston has a sealing face including an elastomeric seal.

Claim 11

The injection device of claim 1 wherein said pilot valve comprises a Schrader-type poppet valve.

Claim 12

An injection device comprising: a housing; a plunger driver within said housing; a valve body within said housing; a pilot valve within a pilot valve chamber in said valve body; a main valve having a main valve seat within said housing and a substantially unbiased main valve piston sealingly engageable to said main valve seat; a gas delivery tube connectable to a compressed gas source and joined to said pilot valve chamber and said main piston chamber, said gas delivery tube having a bleed hole leading to a reservoir; said pilot valve activatable to create a gas pressure difference on opposite sides of said main valve causing it to separate from said valve seat such that compressed gas in said reservoir is released to drive said plunger driver.

Claim 13

An injection device comprising: a housing; a plunger driver within said housing; a valve body within said housing; a pilot valve within a pilot valve chamber in said valve body; a main valve having a main valve seat within said housing and a substantially unbiased main valve piston sealingly engageable to said main valve seat; a gas delivery tube connectable to a compressed gas source and joined to said pilot valve chamber and said main piston chamber, said gas delivery tube having a bleed hole leading to a reservoir; said pilot valve activatable to create a gas pressure difference on opposite sides of said main valve causing it to separate from said valve seat such that compressed gas in said reservoir is released to drive said plunger driver.

Claim 14

An injection device comprising: a housing; a plunger driver slidably positioned within said housing; a piercing body within said housing; a valve body in said housing spaced apart from said piercing body; a gas delivery tube extending from said piercing body to said valve body; a reservoir formed at least by said valve body and said housing, said gas delivery tube having a bleed hole opening to said reservoir; a pilot valve substantially disposed in a pilot valve chamber in said valve body; a main valve seat; a main valve piston slidably disposed within said housing and sealingly engageable against said main valve seat; said main valve piston having a first chamber on a first side thereof, said first chamber connected to said reservoir via a gas passageway, said main valve piston having a second chamber on a second side thereof, said second chamber connecting to said pilot valve chamber; said pilot valve activatable to vent said pilot valve chamber thereby causing said main valve piston separate from said main valve seat such that compressed gas from said reservoir flows past said main valve piston into a plunger chamber to drive said plunger driver.

Claim 15

An injection device comprising: a housing; a plunger driver slidably positioned within said housing; a piercing body within said housing; a valve body in said housing spaced apart from said piercing body; a gas delivery tube extending from said piercing body to said valve body; a reservoir formed at least by said valve body and said housing, said gas delivery tube having a bleed hole opening to said reservoir; a pilot valve substantially disposed in a pilot valve chamber in said valve body; a main valve seat; a main valve piston slidably disposed within said housing and sealingly engageable against said main valve seat; said main valve piston having a first chamber on a first side thereof, said first chamber connected to said reservoir via a gas passageway, said main valve piston having a second chamber on a second side thereof, said second chamber connecting to said pilot valve chamber; said pilot valve activatable to vent said pilot valve chamber thereby causing said main valve piston separate from said main valve seat such that compressed gas from said reservoir flows past said main valve piston into a plunger chamber to drive said plunger driver.

Claim 16

The injection device of claim 12 further comprising a sleeve section on said valve body with said main valve piston slidably displaceable within said sleeve section.

Claim 17

An injection method comprising the steps of: positioning a nozzle of an injection device onto an injection site; activating a biased pilot valve of the device; and allowing an unbiased main valve of the device to open in response to activation of the pilot valve, thereby allowing compressed gas to pass by the main valve to drive injectant from the nozzle.

Claim 18

An injection method comprising the steps of: positioning a nozzle of an injection device onto an injection site; activating a biased pilot valve of the device; and allowing an unbiased main valve of the device to open in response to activation of the pilot valve, thereby allowing compressed gas to pass by the main valve to drive injectant from the nozzle.

Claim 19

The method of claim 14 further comprising the step of supplying compressed gas to the pilot valve.

Claim 20

The method of claim 15 further comprising the step of supplying compressed gas from the reservoir around the pilot valve to the main valve via a gas passageway.

Claim 21

The method of claim 14 further comprising the step of supplying compressed gas to a reservoir.

Claim 22

The method of claim 14 wherein compressed gas is supplied to the pilot valve by connecting a compressed gas cartridge to a gas delivery tube leading to the pilot valve.

Claim 23

The method of claim 18 further comprising the step of bleeding gas from the gas delivery tube to the reservoir.

Claim 24

The method of claim 14 further comprising the step of metering the compressed gas supplied to the pilot valve by passing it through an orifice.

Claim 25

The method of claim 14 wherein said nozzle is on an ampule releasably attached to the injection device, further comprising the step of using the compressed gas flowing by the main valve to drive a plunger into the ampule.

Claim 28

The method of claim 22 further comprising the step of connecting a compressed gas source to the pilot valve chamber, a reservoir and a seat chamber.

Claim 29

An injection device assembly comprising: a device housing; a pilot valve within said device housing connectable to a compressed gas source; an ampule for holding an injectant, said ampule having a nozzle, and said ampule attachable to said device housing; an unbiased main valve operatively connected to said pilot valve, said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive an injectant from said nozzle.

Claim 30

An injection device assembly comprising: a device housing; a pilot valve within said device housing connectable to a compressed gas source; an ampule for holding an injectant, said ampule having a nozzle, and said ampule attachable to said device housing; an unbiased main valve operatively connected to said pilot valve, said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive an injectant from said nozzle.

Claim 31

An injection device comprising: a housing; a plunger driver slidably disposed within said housing; a pilot valve within said housing connectable to a compressed gas source; a main valve operatively connected to said pilot valve, said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive said plunger driver; a cartridge holder attachable to said housing and having a cartridge chamber; a valve body disposed within said housing; a gas delivery tube connecting said cartridge chamber and said valve body; a piercing body spaced apart from said valve body and forming a reservoir therebetween; and a spacer disposed within said reservoir to limit the volume of said reservoir.

Claim 32

An injection device comprising: a housing; a plunger driver slidably disposed within said housing; a pilot valve within said housing connectable to a compressed gas source; a main valve operatively connected to said pilot valve, said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive said plunger driver; a cartridge holder attachable to said housing and having a cartridge chamber; a valve body disposed within said housing; a gas delivery tube connecting said cartridge chamber and said valve body; a piercing body spaced apart from said valve body and forming a reservoir therebetween; and a spacer disposed within said reservoir to limit the volume of said reservoir.

Claim 33

An injection device comprising: a housing; a plunger driver slidably disposed within said housing; a pilot valve within said housing connectable to a compressed gas source; a liner having a liner sheet; a main valve piston having a central counterbore, said main valve piston and said liner seat comprising a main valve; said main valve operatively connected to said pilot valve, and said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive said plunger driver.

Claim 34

An injection device comprising: a housing; a plunger driver slidably disposed within said housing; a pilot valve within said housing connectable to a compressed gas source; a liner having a liner sheet; a main valve piston having a central counterbore, said main valve piston and said liner seat comprising a main valve; said main valve operatively connected to said pilot valve, and said pilot valve activatable to open said main valve such that compressed gas may flow by said main valve to drive said plunger driver.

Claim 35

An injection method comprising the steps of: positioning a nozzle of an injection device onto an injection site; activating a pilot valve of the device; allowing a main valve of the device to open in response to activation of the pilot valve, thereby allowing compressed gas to pass by the main valve to drive injectant from the nozzle; supplying compressed gas to a reservoir; and adjusting the volume of the reservoir.

Claim 36

An injection method comprising the steps of: positioning a nozzle of an injection device onto an injection site; activating a pilot valve of the device; allowing a main valve of the device to open in response to activation of the pilot valve, thereby allowing compressed gas to pass by the main valve to drive injectant from the nozzle; supplying compressed gas to a reservoir; and adjusting the volume of the reservoir.

Claim 37

An injection method comprising the steps of: connecting a compressed gas cartridge to a gas delivery tube leading to the pilot valve, to supply compressed gas to a pilot valve within an injection device; filtering the compressed gas supplied to the delivery tube; positioning a nozzle of the injection device onto an injection site; activating a pilot valve of the device; allowing a main valve of the device to open in response to activation of the pilot valve, thereby allowing compressed gas to pass by the main valve to drive injectant from the nozzle;

Claim 38

An injection method comprising the steps of: connecting a compressed gas cartridge to a gas delivery tube leading to the pilot valve, to supply compressed gas to a pilot valve within an injection device; filtering the compressed gas supplied to the delivery tube; positioning a nozzle of the injection device onto an injection site; activating a pilot valve of the device; allowing a main valve of the device to open in response to activation of the pilot valve, thereby allowing compressed gas to pass by the main valve to drive injectant from the nozzle;