CH253593A

CH253593A - Hollow needle for an injection syringe.

Info

Publication number: CH253593A
Authority: CH
Inventors: Menthen Willem
Original assignee: Menthen Willem
Priority date: 1945-11-05
Filing date: 1946-11-05
Publication date: 1948-03-15
Also published as: NL62636C; BE461333A; FR935581A; GB620780A

Description

  

  



  Hohlnadel f r eine Injektionsspritze.



   Vorliegende Erfindung bezieht sich auf die mit abgeschrägter Mündung und scharfer Spitze versehene Hohlnadel einer   Injektions-    spritze für die subkutane bzw.   intramusku-    läre Einführung arzneilieh wirkender Stoffe.



   Bekanntlich   kann die Einstechung    sol  cher    Hohlnadeln Schmerzen hervorrufen,   @      wenndie    Nadelspitze sehr scharf ist.



  Dies lässt sich an Hand der Fig. 1 und 2 der Zeichnung leicht erklären, welche das Aussenende einer   iibliehen    Injektionsnadel in der   Seitenansicht,teilweise    im Schnitt, bz in der Draufsicht veranschaulichen.



  AN7ird diese Nadel in einen   emporgehobenen      Hautwulst    oder in die Muskelmasse   einge-      stochen,    so macht ; sie zunÏchst ein im   Quer-      schnitt sichelförmiges Loch allmählich    zu  nehmender    Grosse, welches etwa die Halbkreisform erreicht, wenn die Nadel bis zum Querschnitt a-a eingestochen worden ist, wo das halbkreisf¯rmige Loch einen   Durch-    messer   entspreehend    dem   äussern Durch-    messer der Nadel hat.

   Infolge ihrer Naehgiebigkeit wird die Muskelmasse aber in einer ungefÏhr rechtwinklig zur Ebene der AbschrÏgung stehenden Richtung in die   Mitndung hineingedrückt.    Die innere Kante des dann noch ausserhalb des Körpers be   findlichen Teils der ringförmigen Schräg-    flÏche bildet eine Schneide, die bei fortge setzter   Bewegung    der Nadel bestrebt ist, einen Einschnitt in das Fleisch zu machen.



   In Wirklichkeit erfolgt dies aber nicht.



  Die innere Kante der   Sehrägfläche    von a-a bis b bildet nämlich zum gröBeren Teile nicht eine scharfe Scheide, sondern besitzt einen Grat, der sich beim   Abschrägen    der Nadel durch die   übliehe Schleifbearbeitung    gebildet hat. Infolgedessen gleitet das Fleisch über den Grat und weiter über die Schrägfläche empor, was selbstverständlich   schmerzlich    empfunden wird.



   GemäB der Erfindung ist der Rand in der Gegend gegenüber der Nadelspitze so abgerundet, dass dort die äussere Zylinderfläche der Nadel fliessend in die innere Zylinderfläche übergeht.



   Die Fig. 3 und 4 lassen dies kla rerkennen. Die Abrundung des ringförmigen schrÏgen Randes ist bei c etwa   halbkreisför-    mig und nimmt nach a-a hin allmählich ab. Zwisehen a-a und der Nadelspitze ist die Sehrägfläehe etwa eben.



   Die Praxis hat bewiesen, dass das Einstechen einer Kanüle nach der Erfindung in den Körper sogar bei sehr empfindlichen Personen keine nennenswerten Schmerzen hervorruft.  



   PATENTANSPRUCH :
Mit abgeschrägter Mündung und scharfer Spitze versehene Hohlnadel für eine Injektionsspritze, dadurch gekennzeichnet, da¯ der schräge Rand ibrer Miindung in der der
Spitze gegenüberliegenden Gegend   abge-    rundet ist, so dass dort die Ïu¯ere und die innere Zylinderfläehe der Kan le flie¯end incinander  bergehen. 

**WARNUNG** Ende DESC Feld konnte Anfang CLMS uberlappen**.





  



  Hollow needle for an injection syringe.



   The present invention relates to the hollow needle of an injection syringe, which is provided with a beveled mouth and a sharp point, for the subcutaneous or intramuscular introduction of medicinal substances.



   It is well known that piercing such hollow needles can cause pain if the needle point is very sharp.



  This can easily be explained with the aid of FIGS. 1 and 2 of the drawing, which illustrate the outer end of a conventional injection needle in a side view, partially in section, and in plan view.



  If this needle is inserted into a raised skin bulge or into the muscle mass, then it does; it is initially a crescent-shaped hole that gradually increases in size, which reaches approximately the semicircular shape when the needle has been pierced up to the cross-section aa, where the semicircular hole has a diameter corresponding to the outer diameter of the needle .

   As a result of their closeness, the muscle mass is pressed into the opening in a direction that is approximately at right angles to the plane of the bevel. The inner edge of the part of the annular inclined surface that is then still outside the body forms a cutting edge which, with continued movement of the needle, tries to make an incision in the meat.



   In reality, however, this does not happen.



  The inner edge of the sawing surface from a-a to b does not form a sharp sheath for the larger part, but has a burr that has formed when the needle is beveled through the usual grinding process. As a result, the meat slides over the ridge and further up the inclined surface, which is of course painful.



   According to the invention, the edge in the area opposite the needle tip is rounded in such a way that there the outer cylinder surface of the needle merges smoothly into the inner cylinder surface.



   3 and 4 let this be recognized. The rounding of the annular inclined edge is roughly semicircular at c and gradually decreases towards a-a. Between a-a and the point of the needle, the saw surface is roughly flat.



   Practice has shown that sticking a cannula according to the invention into the body does not cause any significant pain even in very sensitive people.



   PATENT CLAIM:
Hollow needle with a beveled mouth and sharp point for a hypodermic syringe, characterized in that the beveled edge of the other mouth is in the
Tip opposite area is rounded, so that there the outer and inner cylindrical surfaces of the canal flow incinently.

** WARNING ** End of DESC field could overlap beginning of CLMS **.

Claims

** WARNING ** Beginning of CLMS field could overlap end of DESC **.

Hollow needle for an injection syringe.

The present invention relates to the hollow needle of an injection syringe, which is provided with a beveled mouth and a sharp point, for the subcutaneous or intramuscular introduction of medicinal substances.

It is well known that piercing such hollow needles can cause pain if the needle point is very sharp.

This can easily be explained with the aid of FIGS. 1 and 2 of the drawing, which illustrate the outer end of a conventional injection needle in a side view, partially in section, and in plan view.

If this needle is inserted into a raised skin bulge or into the muscle mass, then it does; it is initially a crescent-shaped hole that gradually increases in size, which reaches approximately the semicircular shape when the needle has been pierced up to the cross-section aa, where the semicircular hole has a diameter corresponding to the outer diameter of the needle .

As a result of their closeness, the muscle mass is pressed into the opening in a direction that is approximately at right angles to the plane of the bevel. The inner edge of the part of the annular inclined surface that is then still outside the body forms a cutting edge which, with continued movement of the needle, tries to make an incision in the meat.

In reality, however, this does not happen.

The inner edge of the sawing surface from a-a to b does not form a sharp sheath for the larger part, but has a burr that has formed when the needle is beveled through the usual grinding process. As a result, the meat slides over the ridge and further up the inclined surface, which is of course painful.

According to the invention, the edge in the area opposite the needle tip is rounded in such a way that there the outer cylinder surface of the needle merges smoothly into the inner cylinder surface.

3 and 4 let this be recognized. The rounding of the annular inclined edge is roughly semicircular at c and gradually decreases towards a-a. Between a-a and the point of the needle, the saw surface is roughly flat.

Practice has shown that sticking a cannula according to the invention into the body does not cause any significant pain even in very sensitive people.

PATENT CLAIM: Hollow needle with a beveled mouth and sharp point for a hypodermic syringe, characterized in that the beveled edge of the other mouth is in the Tip opposite area is rounded, so that there the outer and inner cylindrical surfaces of the canal flow incinently.