US3905365A - Dental injection gun - Google Patents

Abstract

A dental injection gun is provided for injecting anesthetics into the peridental ligament and comprises a frame having a pistol grip portion carrying a sleeve holder to which is connected a syringe holder, a pusher rod being received in the sleeve holder and being provided with ridges acted upon by an apertured member when the latter is moved by an actuator to eject step-by-step an anesthesia from the gun occasioned by interaction of the apertured member with the ridges on the pusher rod.

Description

United States Patent [191 Colombo DENTAL INJECTION GUN [76] Inventor: Americo Colombo, via Partigiani 24,

Como, Italy [22] Filed: Nov. 23, 1973 21 Appl. No.: 418,315

[30] Foreign Application Priority Data Nov. 25, 1972 Italy 7358/72 [52] U.S. Cl. 128/218 C; 222/309 [51] Int. Cl? A61M 5/315; G01F 11/06 [58] Field of Search 128/218 R, 215, 218 P, 128/218 C, 218 D, 234, 235, 218 A, 236;

[56] References Cited UNITED STATES PATENTS 2,102,591 12/1937 Hagemeier 222/386 X 2,316,095 4/1943 Mead, Jr 128/215 2,750,943 6/1956 Dann 128/218 D [451 Sept. 16, 1975 2,892,457 6/1959 Sturtz 128/218 R 3,110,310 11/1963 Cislak 128/218 C 3,141,583 7/1964 Mapel et a1 128/218 D FOREIGN PATENTS OR APPLICATIONS 449,180 4/1968 Switzerland 128/218 R Primary ExaminerRichard A. Gaudet Assistant ExaminerJ. C. McGowan 1ABSTRACT 4 Claims, 2 Drawing Figures PMEMEB SEP] 6 [975 mwH EQEEEEEEEEES iii m DENTAL INJECTION GUN This invention relates to a dental injection gun.

Various authors have established. the value of intraligamentary anesthesia in dentistry, but in practice it is not generally applied for lack of simple and effective instruments suitable for carrying it out.

It is therefore an object of the present invention to provide a dental injection gun into which a dental syringe can be inserted and conveniently actuated by a dentist to inject an anesthetic into the peridental ligament.

More particularly the invention provides a dental injection gun which comprises handle means similar to the handle of a gun and easily to be gripped by one hand syringe holding means in the upper portion of said handle means, pusher means mounted on said handle means adjacent said syringe holding means rearwardly in the longitudinal extension thereof for movement longitudinally of said syringe said pusher means being arranged to act upon a piston in said syringe and control lever means pivotally mounted on said handle means and pivotally connected to said pusher means for imparting said longitudinal movement thereto.

A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which FIG. 1 is a schematic side view of the dental injection gun; and FIG. 2 is an axial part cross-section taken along line IIII of FIG. 1.

Referring to the drawing, the dental injection gun shown therein has a syringe holder comprising a slottedsleeve 2 secured to asleeve holder 3 by means of a bay onet or screw coupling, and adapted to receive a syringe I. Thesleeve holder 3 is an integral part of the frame of the gun, the frame being shaped to provide a pistol grip as hereinafter more fully disclosed. Thesyringe 1 has a piston (not shown) actuatable by apusher rod 6 provided with equally spaced transverse grooves defined between ridges on the rod and longitudinally shiftably mounted in a axial bore provided in thesleeve holder 3 rearwardly in the longitudinal extension of thesyringe 1. Mounted on thepusher rod 6 is alug 5 having a hole therein slightly larger than the diameter of thepusher rod 6 which extends through this hole. A double-armed bracket 9 having an arm on either side of thepusher rod 6 has one end pivotally connected at 10 to a forkedend 11 of acontrol lever 12 in the form of a trigger which is mounted for swinging movement about apivot 13. The other end of thebracket 9 is pivotally connected at 7 to the bottom end of thelug 5. The rear end of thepusher rod 6 is provided with acountersunk knob 8 to prevent thelug 5 from slipping off thepusher rod 6 and permit thelug 5 to be longitudinally adjusted in its position on thepusher rod 6. Atorsion spring 25 surrounds thepivot 7 and is supported with one end against thelug 5 and the other end against thebracket 9 whereby to normally incline thelug 5 in the direction shown in FIG. 1 in the non-actuated position oflever 12. Ablade spring 14 is fixed laterally on thesleeve holder 3 and has apin 15 at one end engaging on the ridges on thepusher rod 6. A similar blade spring is provided on the other side of thesleeve holder 3 as shown in FIG. 2. It will be appreciated that by virtue of thetorsion spring 25 and the pivotal mounting oflug 5 aboutpivot 7, the lug may be moved into an oppositely inclined position relative to that shown in FIG. 1 through an intermediate perpendicular position.

Thepusher rod 6 with itscontrol lever 12 is mounted on ahandle 16 in the form of a pistol grip. On the side adjacent thecontrol lever 12 thehandle 16 has aprojection 23 and therebelow a pair ofrecesses 24 suitably shaped to receive a finger in each of them. Anelongated leaf Spring 17 is located within and extends longitudinally of thehandle 16 and is fixed at one end by means of ascrew 18 to an interior lower wall of thehandle 16. The otherfree end 19 of theleaf spring 17 is provided with a hole through which extends arod 20 provided with acollar 21 engaging theleaf spring 17 adjacent the hole at thefree end 19 thereof, the diameter of thecollar 21 being larger than that of the hole in theleaf spring 17. Therod 20 is mounted within thehandle 16 but has a free end projecting therefrom and engaging the rear side of thecontrol lever 12. So theleaf spring 17 urges therod 20 against thecontrol lever 12 to keep the latter in its rest position in which thepusher rod 6 does not act upon the piston of the syringe l.

The operation'of the dental injection gun is as follows: I

Thepusher rod 6 is pushed back as far as it will go by pulling theknob 8 while keeping thelug 5 lightly pressed forward with a finger, thus allowing the lug to ride over the ridges of thepusher rod 6. In this position of the pusher rod 6'thesyringe 1 can be easily inserted in thesyringe holder 2, 3 after thecoupling 4 has been unscrewed or released. Thesyringe 1 complete with injection needle is then locked in thesyringe holder 2, 3

by means of thecoupling 4. Then the gun is ready for the injection operation.

For the injection operation itself the injection gun is held by thehandle 16 in one hand with the thumb on one side thereof and the small finger and the ring finger on the other side in therecesses 24 below theprojection 23 and thecontrol lever 12 is pulled rearwardly by the forefinger and the middle fingerof the same hand placed in front of thelever 12 above theprojection 23. Thereby thepusher rod 6 is moved stepwise forwardly and as the front end of thepusher rod 6 acts on the rear of the piston in the syringe l, the syringe piston is moved forwardly and injects the anesthetic from thesyringe 1 into the peridental ligament. Each actuation of thecontrol lever 12 causes thepusher rod 6 to advance by one step the length of the steps being determined by the length of travel of thelug 5. After each pull exerted on thecontrol lever 12 the latter is returned to its forward position by theleaf spring 17, thelug 5 riding over the ridges under the action of theportion spring 25. In this manner a gradual injection operation is ensured. Theblade springs 14 essentially have the purpose of frictionally resisting the movement of thepusher 6 by virtue of engagement ofpin 15 with the ridges on thepusher rod 6, whereas the torsion spring surrounding thepivot 7 ensures that thelug 5 will engage the ridges of thepusher rod 6 during the forward movement of the control lever. The slots in thesleeve 2 permit to observe the movement of the syringe piston. However, the end of the stroke of the syringe piston can also be checked by observing the degree of movement of theknob 8 relative to sleeve holder When it has thus been established that the syringe piston has reached the forward end of its stroke, the injection operation is completed. The syringe is withdrawn from the mouth of the patient and the syringe can be removed from the injection gun by unlocking the coupling'4 as described above.

Although a preferred embodiment of the invention has been described herein in detail and illustrated in the accompanying drawing it is to be understood that the invention is not limitedto this precise embodiment and that numerous changes and modifications'obvious to one skilled in the art may be made therein without departing from the scope and spirit of the invention.

I claim: I

1. A dental injection gun comprising a frame having a portion thereof shaped to provide a pistol grip, an elongate sleeve holder integral with the frame and being oriented substantially perpendicularly relativeto the pistol grip portion of the frame, an elongate sleeve adapted to hold a syringe and being detachably connected to said sleeve holder for axial alignment therewith and extension therefrom, an elongate rod received .in said sleeve holder for movement relative thereto and being adapted to act at one end thereof on a charge of anesthetic in said sleeve when moved in a predetermined direction relative to said sleeve holder, said rod being formed with a plurality of ridges on its outer surface which ridges extend generally transverse .to the axis of the elongate rod and terminating in an enlarged head at that end of the rod opposite said one end thereof, actuating means for actuating said rod and comprising lever arms one of which is a trigger arm extending in the general direction of said pistol grip and being pivotally mounted to said frame with one end thereof proximate said rod and its opposite free end normally urged in a direction away from the pistol grip portion of the frame, said lever arms'including a double arm bracket pivotally mounted at one end thereof to said one end-of said trigger arm, a lug di sposed generally transversely to the axis of the rod and being mounted to the opposite end ofthe bracket for pivotal movement about an axis transverse to the axis of the rod, said lug beingformed with a holeof a diameter slightly larger than the largest diameter of the ridges on said rod, the latter passing through said hole in said lug, and torsion spring means for normally urging said lug into an inclined position ina direction opposite to the direction of advancement of said rod by said actuating means and in which position of the lug the surface defining said hole being-ingripping engagement with the ridges on the rod, said lug being movable into an oppositely inclined position through an intermediate perpendicular position.

2. The dental injection gun according toclaim 1, wherein the spring means biasing the aperturcd member is a torsion'spring. I

3. The dental injection gun according toclaim 1, wherein the piston grip is formed with a projection providing multiple finger engaging surfaces.

4. The dental injection gun according toclaim 1, there being included means on the sleeve holder acting on said ridges for frictionally holding the rod in the position in which it is moved

Claims (4)

1. A dental injection gun comprising a frame having a portion thereof shaped to provide a pistol grip, an elongate sleeve holder integral with the frame and being oriented substantially perpendicularly relative to the pistol grip portion of the frame, an elongate sleeve adapted to hold a syringe and being detachably connected to said sleeve holder for axial alignment therewith and extension therefrom, an elongate rod received in said sleeve holder for movement relative thereto and being adapted to act at one end thereof on a charge of anesthetic in said sleeve when moved in a predetermined direction relative to said sleeve holder, said rod being formed with a plurality of ridges on its outer surface which ridges extend generally transverse to the axis of the elongate rod and terminating in an enlarged head at that end of the rod opposite said one end thereof, actuating means for actuating said rod and comprising lever arms one of which is a trigger arm extending in the general direction of said pistol grip and being pivotally mounted to said frame with one end thereof proximate said rod and its opposite free end normally urged in a direction away from the pistol grip portion of the frame, said lever arms including a double arm bracket pivotally mounted at one end thereof to said one end of said trigger arm, a lug disposed generally transversely to the axis of the rod and being mounted to the opposite end of the bracket for pivotal movement about an axis transverse to the axis of the rod, said lug being formed with a hole of a diameter slightly larger than the largest diameter of the ridges on said rod, the latter passing through said hole in said lug, and torsion spring means for normally urging said lug into an inclined position in a direction opposite to the direction of advancement of said rod by said actuating means and in which position of the lug the surface defining said hole being in gripping engagement with the ridges on the rod, said lug being movable into an oppositely inclined position through an intermediate perpendicular position.

2. The dental injection gun according to claim 1, wherein the spring means biasing the apertured member is a torsion spring.

3. The dental injection gun according to claim 1, wherein the piston grip is formed with a projection providing multiple finger engaging surfaces.

4. The dental injection gun according to claim 1, there being included means on the sleeve holder acting on said ridges for frictionally holding the rod in the position in which it is moved.

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