SCALPEL

Abstract: Scalpel comprising a shank (14) having a holder for releasably mounting a surgical blade (10). There is formed on the blade (10) proper, consisting of metal, by injection molding a body (11) of plastic material forming a ball (13). The holder includes a sleeve (15) threadedly engaged with the shank at one end thereof to be screwed axially along the shank. The sleeve forms a ball socket (16) to receive the ball (13) of the blade therein. A clamping rod (21) extends axially within the socket between the shank and the ball to engage and disengage said ball by the sleeve being screwed on the shank. The end of the clamping rod (21), which is adjacent the ball forms a circular sharp edge (22) of a diameter which is substantially smaller than the diameter of the ball, to cut into the plastic material of the ball when the sleeve is screwed to engage the clamping rod with said ball.

Description: TITE OF INVENTION: SCALPEL The invention relates to a scalpel comprising a shank having a holder for releasably mounting a surgi¬ cal blade, said holder including a sleeve threadedly engaged with the shank at one end thereof to be screwed axially along the shank and forming a ball socket, a ball on the blade to be received in said ball socket, and a clamping rod extending axially within the socket between the shank and the ball to engage and disengage .said ball by the sleeve being screwed on the shank. A scalpel of this type is shown and described in CH-A-490 072. The rod projecting from the shank and being integral therewith, at the free end forms a seat which can be engaged with and can partially receive therein the ball of the blade by screwing the sleeve on the shank so that the ball will be clamped in the ball socket. The ball and the ball socket form a uni¬ versal joint which allows the blade to be adjusted to different angles on the shank and to be locked in the desired angular position. Many types of surgery cause specific access prob¬ lems, and this is particularly true as far .as oral surgery is concerned (gingival operations, extraction of wisdom-teeth etc) , joint surgery and surgical in- tervention in ears, nose and throat. In these cases it may be difficult to obtain access by means of a common straight scalpel. It may be necessary to use angled scalpels or reversed knives which are used for example in gingival operations. Scalpels of the type mentioned above have been proposed in order to allow extraordi¬ nary access in different surgical operations of any type. In the prior art scalpel referred to above the ball and thus the blade is locked in the desired angu¬ lar position by the frictional engament between the ball at one hand and the seat of the rod and the ball socket at the other hand, and accordingly it is ne¬ cessary to securely tighten the sleeve on the shank to be sure that the angular position of the blade will not change or the blade will come loose when the scal¬ pel is being used. The purpose of the present invention is to pro¬ vide a scalpel of the type referred to above wherein the blade is more securely anchored to the shank in the desired angular position, which is an absolute central requirement in oral surgery wherein an instru¬ ment of this type definitely shall not be allowed to come loose. For said purpose the scalpel of the invention has obtained the characteristic features appearing from claim 1. In order to explain the invention in more detail an embodiment thereof will be described below refer- ence being made to the accompanying drawing in which FIG 1 is a side view of a scalpel of the inven¬ tion, FIG 2 is an enlarged side view of the blade and an element forming the cirkular sharp edge to be engaged with the ball, said element being partly shown in axial cross sectional view, FIG. 3 is a fragmentary enlarged axial cross sec¬ tional view of the blade end of the scalpel without the blade, and FIG. 4 is a view similar to that in FIG. 3 with the blade mounted to the shank. The surgical blade shown in the drawing comprises a metal portion 10 forming the actual blade (the knife edge) , and on this metal portion a plastic body 11 is formed by injection molding, said plastic body forming a neck 12 and a ball 13. On the shank 14 of the scal¬ pel there is provided for the attachment of the blade a sleeve 15 which forms a spherical ball socket 16 available from the outside through a side aperture 17. Moreover, the sleeve has a slot 18 joining the aper¬ ture 17. The sleeve is threadedly engaged with the shank, and for this purpose the shank forms a thicker end portion 19 with a bore 20 having an inside screw thread. The sleeve 15 having an outside screw threaded engages the inside screw thread of the portion 19 and can be displaced axially into and out of the bore by the sleeve being rotated and thus being screwed on the shank. In the sleeve a clamp rod 21 is received, and this rod has at the end adjacent the ball socket a circular sharp edge 22, FIG. 2, having a diameter which is considerably smaller than the diameter of the ball 13. The other end of the clamp rod can be engaged with an abutment surface 23 formed by the shank at the bottom of the bore. The ball 13 on the blade can be inserted into the ball socket 16 passing through the side aperture 17. The ball can be freely rotated in the ball socket for the adjustement of the blade to a desired rotated or angled position the neck 12 being received by the slot 18 at angling, and can be locked with the blade in the desired position by screwing the sleeve 15 axially on the shank so that the circular sharp edge 22 of the clamp rod will be engaged with the ball and will cut into the plastic material of the ball the clamp rod being supported by the abutment surface 23. The hard- ness of the plastic material (preferably carbon fibre reinforced plastic material) must of course be chosen such that it is lower than the hardness of the materi¬ al of the clamp rod, usually metal, so that it is possible for the edge of the clamp rod to cut into the material. The blade 10 can be rapidly locked in the desired position and in the desired angle "around the horizon" over about 2/3 of an imagined sphere. Since the blade can be rotated over 360 degrees and can be given the proper direction in all conceivable posi- tions the need of having several scalpels of different types will be eliminated. If it is desired to change slightly the angular position in which the blade has been locked this can easily be done. The sharp edge of the clamping rod will cut into the ball in the new po- sition without any risk of the clamping rod positively moving the ball back to the previous position as could happen if the clamping rod engaged the ball at a solid end and made only a depression in the ball. In that case the clamping rod may tend to land at the bottom of the depression made in the previous position there¬ by causing slight rotation of the ball to said posi¬ tion. Due to the stepless ad ustment of the blade in a desired plane and in a desired angle the incision in many regions will be facilitated, and extreme access in the oral cavity and other cavities in the body will be achieved. The surgical blade of the invention due to the fact that the attachment portion thereof com¬ prises a plastic portion formed thereon by injection molding can be manufactured at very low costs so that the blade is a cheap one-way product and thus can be replaced at low costs when necessary and will be se¬ curely anchored in the position of use thereof. Preferably the plastic body consists of a plastic material which can be sterilized,, and the shank, sleeve and clamp rod consist of stainless steel.

Claims: CLAIMS 1. Scalpel comprising a shank (14) having a holder for releasably mounting a surgical blade (10) , said holder including a sleeve (15) threadedly engaged with the shank at one end thereof to be screwed ax¬ ially along the shank and forming a ball socket (16) , a ball (13) on the blade to be received in said ball socket, and a clamping rod (21) extending axially within the socket between the shank and the ball to engage and disengage said ball by the sleeve being screwed on the shank, c h a r a c t e r i z e d in that there is formed on the blade (10) proper, con¬ sisting of metal, by .injection molding a body (11) of plastic material forming the ball (13) , and that the end of the clamping rod (21) , which is adjacent the ball forms a circular sharp edge (22) of a diameter which is substantially smaller than the diameter of the ball, to cut into the plastic material of the ball when the sleeve is screwed to engage the clamping rod with said ball. 2. Scalpel as in claim 1 wherein the sleeve (15) is screwed into a bore (20) formed by the shank (14) . 3. Scalpel as in claim 2 wherein the clamp rod (21) as a separate element is received by the sleeve (15) and said bore (20) to be engaged between the b ' all (13) and an abutment surface (23) formed by the shank (14) at the bottom of the bore.

Inventors: LUNDGREN DAN, LUNDGREN, DAN
Applicants: LUNDGREN DAN, LUNDGREN, DAN
Application year: 1989
Main classification: A61B17
IPC codes: A61B17