Injection apparatus with filter

Claim 2

In fluid medicament injection apparatus, the combination comprising housing means having a chamber therein, filter means in said chamber for filtering fluid medicament flowing therethrough, said filter means dividing said chamber into a pair of chamber portions, and cannula means having spaced openings therein, said filter and cannula means being relatively movable to effect the positioning of one of said openings from within one of said chamber portions to a location within the other of said chamber portions.

Claim 3

The apparatus according to claim 1 wherein said filter means has an aperture therein for receiving said cannula means.

Claim 4

The apparatus according to claim 2 wherein said filter means includes puncturable seal means normally closing said aperture and which is punctured by said cannula in response to relative movement between said filter and cannula means.

Claim 5

The apparatus according to claim 2 wherein said cannula means is closed at one end and is sized to move in said aperture and substantially close said aperture.

Claim 6

The apparatus according to claim 4 wherein said one opening is disposed in the side wall of said cannula means.

Claim 7

The apparatus according to claim 2 wherein said housing means comprises a syringe barrel.

Claim 8

The apparatus according to claim 2 wherein said housing means comprises a member having one end with an opening adapted to receive one end of a syringe barrel, and an opposite end having an opening adapted to receive said cannula means.

Claim 9

The apparatus according to claim 1 wherein said filter means comprises a filter element of metal.

Claim 10

In fluid medicament injection apparatus, the combination comprising housing means having a fluid chamber therein, filter means having an aperture therein and disposed in said chamber for filtering fluid flowing therethrough, said filter means dividing said chamber into distal and proximal chamber portions, cannula means, and coupling means connected to said cannula means and coupled to said housing means for movement relative thereto for selectively positioning said cannula means in a first position with said cannula means in direct fluid communication with said distal chamber and a second position with said cannula means in direct fluid communication with said proximal chamber portion and in fluid by-passing relation with said filter means and said distal chamber portion, said cannula means being movable in said aperture.

Claim 11

In fluid medicament injection apparatus, the combination comprising housing means having a fluid chamber therein, filter means having an aperture therein and disposed in said chamber for filtering fluid flowing therethrough, said filter means dividing said chamber into distal and proximal chamber portions, cannula means, and coupling means connected to said cannula means and coupled to said housing means for movement relative thereto for selectively positioning said cannula means in a first position with said cannula means in direct fluid communication with said distal chamber and a second position with said cannula means in direct fluid communication with said proximal chamber portion and in fluid by-passing relation with said filter means and said distal chamber portion, said cannula means being movable in said aperture.

Claim 12

The apparatus according to claim 9 further including piston means slidable in said housing means for effecting fluid pressure in said chamber.

Claim 13

The apparatus according to claim 10 wherein said cannula comprises a hypodermic needle having distal and proximal openings respectively disposed in distal and proximal end portions thereof, said proximal end portion moves in said aperture during movement of said cannula from one of said first and second positions to the other of said first and second positions.

Claim 14

The apparatus according to claim 11 wherein said filter means includes seal means normally closing said aperture, and said proximal end portion has a pointed end for puncturing said seal means when said proximal end portion moves in said aperture.

Claim 15

The apparatus according to claim 11 wherein the proximal end of said proximal end portion is closed, said proximal opening is in the side wall of said proximal end portion, and said needle is sized to maintain said aperture substantially closed when said needle is in said first position and also when it is in said second position.

Claim 16

The apparatus according to claim 11 wherein said coupling means comprises a hub, said housing means comprises a main barrel portion, and a distal extensIon portion having a smaller outer diameter than that of said barrel portion for receiving said hub, and a generally radially inwardly extending portion connected between said extension portion and said barrel portion, said hub and said extension portion having cooperating abuttment means thereon for selectively locating said hub relative to said housing means to position said cannula selectively in said first and second positions.

Claim 17

The apparatus according to claim 14 wherein said filter is disposed in said housing means in engagement with the juncture between said barrel and said extension portions.

Claim 18

A hypodermic syringe comprising a hub, a hypodermic needle fixed to said hub and having distal and proximal openings therein, a barrel having a bore, and a distal end portion receiving said hub to connect said needle in fluid communication with said bore, a filter disposed in said bore adjacent to said distal end portion and dividing said bore into distal and proximal chambers, said filter having a normally closed aperture therein aligned in relation with said needle, said hub and said needle being movable relative to said barrel to selectively position said proximal opening in said barrel on the distal side of said filter with said needle in series fluid communication with said distal and proximal chambers and said filter, and to position said proximal opening in said barrel on the proximal side of said filter with said needle extending in said aperture in direct fluid communication with said proximal chamber and in fluid by-passing relation with said filter and said distal chamber, and plunger means including piston means slidable in said bore for moving fluid through said needle.

Claim 19

A hypodermic syringe comprising a hub, a hypodermic needle fixed to said hub and having distal and proximal openings therein, a barrel having a bore, and a distal end portion receiving said hub to connect said needle in fluid communication with said bore, a filter disposed in said bore adjacent to said distal end portion and dividing said bore into distal and proximal chambers, said filter having a normally closed aperture therein aligned in relation with said needle, said hub and said needle being movable relative to said barrel to selectively position said proximal opening in said barrel on the distal side of said filter with said needle in series fluid communication with said distal and proximal chambers and said filter, and to position said proximal opening in said barrel on the proximal side of said filter with said needle extending in said aperture in direct fluid communication with said proximal chamber and in fluid by-passing relation with said filter and said distal chamber, and plunger means including piston means slidable in said bore for moving fluid through said needle.

Claim 20

The hypodermic syringe according to claim 16 further including seal means normally closing said aperture, and wherein said needle pierces said seal means when moving from one of said sides of said filter to the other of said sides.

Claim 21

The hypodermic syringe according to claim 16 wherein said aperture is closed by said needle when said proximal opening is on said distal side of said filter and when it is on said proximal side of said filter.

Claim 22

The hypodermic syringe according to claim 16 wherein said filter comprises an annular disc-like member formed of metallic fibers.

Claim 23

A filter unit for use in filtering fluid medicament in medicament injection apparatus comprising a housing having a chamber, a filter having two faces and means for receiving a needle end, said filter being disposed in said chamber dividing said chamber into distal and proximal chamber portions respectively adjacent said faces, said housing having a proximal end portion for coupling a hypodermic syringe barrel thereto in fluid communication with the chamber, said housing having a distal end portion for sealingly receiving the hub of a needle and hub assembly for connecting the proximal opening end of the needle of said assembly selectively in said distal chamber and said proximal chamber.

Claim 24

A filter unit for use in filtering fluid medicament in medicament injection apparatus comprising a housing having a chamber, a filter having two faces and means for receiving a needle end, said filter being disposed in said chamber dividing said chamber into distal and proximal chamber portions respectively adjacent said faces, said housing having a proximal end portion for coupling a hypodermic syringe barrel thereto in fluid communication with the chamber, said housing having a distal end portion for sealingly receiving the hub of a needle and hub assembly for connecting the proximal opening end of the needle of said assembly selectively in said distal chamber and said proximal chamber.