KNIFE, IN PARTICULAR FOR SURGICAL PURPOSES

Abstract: Knife, comprising a handle (1) and an exchangeable cutting blade, in particular a knife for surgical purposes, which cutting blade comprises a cutting part (3) and a strip-shaped holding part (4), which strip-shaped part is surrounded by a polygonal plastic sleeve (5) which at one end is firmly connected near the cutting part to the strip-shaped part and also encloses the strip-shaped part with play, and which handle is provided with a fixing part (2) which can accommodate the strip-shaped part in a snug fit on the inside and on the outside can engage in a snug fit in the space between strip-shaped part and inside of the plastic sleeve, and in that locking means (6) are present between at least one wall of the plastic sleeve and at least one side of the fixing part of the handle.

Description: Knife, in particular for surgical purposes. The invention relates to a knife, comprising a handle and an exchangeable cutting blade, in particular a knife for surgical purposes, which handle is provided at one end with means for holding the cutting blade. Such knives have already been in use for decades as surgical knives, while the cutting blades can be of different shapes, depending on the purpose for which the knife is intended. In recent years such knives have also been used for other purposes, on account of their handiness and relatively low price. In the case of a known knife (see, for example, US Patent Sp e cification 1,448,305) one end of the handle is provided with pin-shaped projections at short intervals and the cutting blade is provided with recesses at corresponding places. When the cutting blade is being fitted on the end of the handle the pin-shaped projections are pushed through the recesses and the cutting blade is secured by shifting. This known knife has the disadvantage that the slit-shaped recess and the cutting blade weaken and there is still a risk of injuries when the cutting blade is being inserted or removed. The object of the invention is to avoid these disadvantages. This is achieved according to the invention in that the cutting blade comprises a cutting part and a strip-shaped holding part, which strip-shaped part is surrounded by a polygonal plastic sleeve which is firmly connected at one end near the cutting part to the strip-shaped part and also encloses the strip-shaped part with play, in that the handle is provided with a fixing part which can accommodate the strip-shaped part in a snug fit on the inside and on the outside can engage in a snug fit in the space between strip-shaped part and inside of the plastic sleeve, and in that locking means are present between at least one wall of the plastic sleeve and at least one side of the fixing part of the handle. When the cutting blade is being exchanged it can be gripped by the plastic sleeve, as a result of which the chance of injuries is reduced. Moreover, the cutting blade is not weakened. The invention will be explained in greater detail with reference to the drawing, in which: Fig. 1 is a perspective side view of a handle of a knife according to the invention; Fig. 2 is a corresponding side view of the other side; Fig. 3 s a perspective side view of the exchangeable cutting blade, which can be fixed by sliding onto a handle according to Figs. 1 and 2; Fig. is a longitudinal section through a cutting blade according to the invention; and Fig. is a perspective view of another type of cutting blade. The handle 1 according to Figs. 1 and 2 can be of any desired cross-section and of any desired length. Nor is the material from which it is made, generally metal, of importance for the invention. At one end the handle 1 is provided with a fixing part 2 which is integral therewith, and which in cross-section is prsferably the shape of a C with right angles. A straight-walled tuoe can, however, also be used. The fixing part 2 is preferably made of metal. A lobe 2a is present on the rear side of one wall of the fixing part 2, near the free end thereof (see Fig. 2) . As shown in Fig. 4, which shows a longitudinal section through a cutting blade, the cutting blade comprises a cutting part 3 and a strip-shaped part 4 which is integral therewith, and a fixing sleeve 5- The cutting part 3 can be of any desired shape and conprises one piece of metal with the strip-shaped part 4. This strip-shaped part 4 is identical for all types of cutting blades. The plastic sleeve encloses the strip-shaped part 4 with play and at the front side is connected at a to the metal part 3, 4. The cross-section shape and size of the strip-shaped part 4 am such that this part 4 can be slid without play into the fixing part 2 of the handle 1. The inner cross-section and size of the plastic sleeve 5 are such that the sleeve 5 can be slid without play over the fixing part 2 of the handle 1. In at least one wall of the plastic sleeve a tilting catch element 6 is present, comprising two parts 6a and 6b and a hinge pin 6c which is integral therewith, which catch element 6 is fitted in a window of the above-mentioned wall of the plastic slseve - This catch element 6 is preferably integral with the plastic sleeve and such a catch element 6 is preferably present in two opposite walls of the plastic sleeve 5« This simplifies the fixing of the cutting blade on the handle, because the position in which fixing takes place then does not matter. The part 6b of the catch element 6 situated more in the slseve 5 serves as the catch for the lobe 2a on the fixing part 2 of the handle 1. After sliding of the sleeve 5 onto the part 2, the catch 6b engages by itself behind the lobe 2a. The locking is released by pressing on the part 6a, and the cutting blade can then be removed. For fitting or removal of the cutting blade, the latter can be gripped by the sleeve 5. so that there is less of a chance of injury. Grooves 6d, in which the lobe 2a can slide, are present in th= inside of the sleeve 5- Fig. shows in perspective a different type of cutting blade, in which the sleeve 5 is extended forward with a part 7 which is integral therewith and has a transverse face 8 at the free end. The cutting blade 3 projects over a short distance, for example 0.1 - 0.3 mm, relative to the face 8. A recess 8a is present in said face 8, in order to improve the view of the cutting blade 3- Such a type of cutting blade prevents too deep cuts. The surgical knife according to the invention, which can also be used for other purposes, offers great advantages for rapidly changing a cutting blade without any risk.

Claims: C L A I M S 1. Knife, comprising a handle and an exchangeable cutting blade, in particular a knife for surgical purposes, which handle is provided at one end with means for holding the cutting blade, characterized in that the cutting blade comprises a cutting part and a strip-shaped holding part, which strip-shaped part is surrounded by a polygonal plastic sleeve which at one end is firmly connected near the cutting part to the strip-shaped part and also encloses the strip-shaped part with play, in that the handle is provided with a fixing part which can accommodate the strip-shaped part in a snug fit on the inside and on the outside can engage in a snag fit in the space between strip-shaped part and inside of the plastic sleeve, and in that locking means are present between at least one wall of the plastic sleeve and at least one side of the fixing part of the handle. 2. Knife according to Claim 1, characterized in that the plastic sleeve is the shape of a rectangle. 3- Knife according to Claim 1 or 2, characterized in that ths fixing part of the handle in cross-section is the shape of a C with right angles. 4. Knife according to Claim 1 or 2, characterized in that th= fixing part of the handle in cross-section is the shape of a polygonal tube. 5. Knife according to Claim 1, 2, 3 or 4, characterized in that a run-on lobe which can interact with a catch in the inside of at least one wall of the plastic sleeve is formed on at least one wall of the fixing part of the handle. 6. Knife according to Claim 5- characterized in that the plastic sleeve is provided with a catch on two opposite walls. 7. Knife according to Claim 6, characterized in that the catch comprises two parts which pivot about a pin in the wall of the sleeve, one part serving for locking and the other part for unlocking. 8. Knife according to one or more of the preceding claims, characterized in that the cutting part of the cutting blade is accommodated between a transverse face which is connected to the plastic sleeve and projects a slight depth relative to the transverse face.

Inventors: ISTHA JOHANNES, VAN DER MERWE CATHARINA HELENA, ISTHA, JOHANNES, VAN DER MERWE, CATHARINA, HELENA
Applicants: ISTHA IND DESIGN BV, ISTHA INDUSTRIAL DESIGN B.V.
Application year: 1992
Main classification: A61B17
IPC codes: A61B17, B26B1, B26B5