GB2189735A - Surgical forceps - Google Patents

Abstract

In a surgical forceps in which a rod (4) extending within a shaft (1) is turned by actuation of a forceps handle (20) via a bevel gear transmission (12,14) located within a housing (5) to close and open forceps jaws (2,3), the transmission is operated by a thrust rod (16) extending outwardly of the housing and connected to the handle on the outside of the housing. A cylindrical outer housing (6) receiving the transmission contains a bearing case (7) proximally delimiting the housing with a bearing (7'). The proximal bearing has extending through it the rod (16) which is axially displaceable by means of the movable forceps handle (20) for the purpose of actuating the bevel gear transmission, and the proximal extremity of the shaft and of the rotary rod is exchangeably installed in the distal end of the housing which is closed off by means of a cap (13). <IMAGE>

Description

SPECIFICATION Surgical forceps The invention relates to surgical forceps, for example for arthroscopic application, in which a cutting edge of a pair of forceps jaws which is pivotable by means of a rotary rod extending through the forceps shaft cooperates with a stationary cutting edge at the distal extremity of a shaft, the rotary rod being twistable by means of a movable branch of the forceps handle via two bevel gears which mesh with each other and are positioned at right angles to each other in a housing connected to the shaft and forming a stationary branch of the forceps handle.

Forceps of the aforesaid nature disclosed in German Utility Model 8418993, are provided with a housing protecting the transmission elements against soiling, which is rigidly joined to the one branch of a forceps handle, whereas the movable forceps handle branch passes through a slot of the housing and via a link actuates a bevel gear mounted on a transverse spindle, which meshes with an axially aligned bevel gear. The latter bevel gear is situated on the proximal extremity of a rotary rod which extends through a shaft and whose pivotal displacement allows the one cutting edge of a pair of forceps jaws to pivot towards a cutting edge fixedly joined to the shaft, forthe purpose oftaking tissue sections.Since the movable forceps handle branch transverses a slot inthe housing, dirt mayenterand result in obstructions during utilisation ofthe forceps. Furthermore, a pair of forceps constructed in this manner presents problems of hygiene and may lead to an accidentaltransferofgerms.

The present invention consists in surgical forceps comprising a housing; a aforceps shaft having proximal and distal ends, the proximal end being secured to an projecting into the housing and the distal end having thereon a fixed cutting edge of a pair of forceps jaws; a rotary rod, extending axiallythrough said shaft and having proximal and distal ends, its proximal end projecting from the shaft within the housing and its distal end having thereon a cutting edge rotatable with the rod to cooperate with the fixed cutting edge and form therewith a pair offorceps jaws; means within the housing for actuating the rotatable cutting edge by rotating the rod, said means including an axially displaceable thrust rod extending outwardly from the housing through a sealed bearing at the proximal end ofthe housing; and a movable forceps handle connected to the thrust rod outside the housing to effect axial movement thereof to actuate the rotatable cutting edge.

It is possible by means of the invention to protect the transmission elements in a forceps ofthe above type by using a wholly sealed housing. The forceps housing may be constructed in such a way that forceps inserts with different forceps apertures may be replaceablyjoined to the transmission and handle section.

In a preferred embodiment of the invention, a cylindrical housing is delimited at its proximal end by a bearing of an internal bearing case for two bevel gears, forming part of the actuating mechanism said bearing being traversed in sealed manner by the thrust rod which is axially displaceable by means of the movable forceps handle, and is delimited at its distal end by a cap which may be screwed on, by means of which the proximal extremity of the shaft and of the rotary rod are releasably secured. The housing receiving the transmission and the forceps inserts is thereby wholly shut off and the actuation of the bevel gears with the coupled rotary rod for the movable cutting edge of the forceps jaws occurs via a thrust rod which passes through a proximal bearing ofthe housing and is axially displaceable by means of the movable handle.At the other extremity of the housing, the proximal extremity of the shaft and of the rotary rod is secured by means of a cap which may be screwed on to the cylindrical housing or fastened in another appropriate manner and coupled to the drive system, so-that replacement of the shaft and rotary rod by shafts and rotary rods having modified forceps jaws is rapid and easy.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings wherein: Figure 1shows a sideviewofsurgicalforceps according to the invention; Figure2 shows an enlarged longitudinal cross-section through the forceps case containing the transmission; and Figure 3 shows a cross-section through an example of a set of forceps jaws.

The surgical forceps of Figure 1 comprise a shaft 1 having fixedlyjoined to its distal end a cutter2 of a pair offorceps jaws, the other movable cutter 3 of which is coupled to a rotary rod 4which extends through the shaft 1 and which may be rotationally displaced from its proximal end by means ofthe transmission installed in the housing 5.

The housing 5 comprises an outer cylindrical housing 6 and an internal bearing case 7 which is provided at its proximal extremity with a bearing 7 which may be releasablyjoined to the cylindrical housing 6 by screwing, or in another known manner, and with a bearing 7" at its distal extremity. The bearing case 7 is open at least at the top between the bearings 7' and 7", and is closed off by means ofthe cylindrical housing 6.

At its proximal extremity, the forceps shaft 1 is firmly joined to a coupling member 8 comprising a radial flange 8'. The radial flange 8' has a radial groove 8" wherein is engaged a pin 7" immobilised in the bearing 7", by means of which the shaft 1 is untwistablysecured in the housing. The rotary rod 4 protrudes from the proximal extremity of the shaft 1, and this extremity is provided for example with an externally non-circular coupling element 10 which engages in the hollow boss 11 of a bevel gear 12 rotatably mounted in the bearing 7" and is coupled to the boss by virtue ofthe complementary form of the boss cavity. The housing 6 is delimited at its distal end by a cap 13 which may be screwed on to the housing extremity or is otherwise releasably secured thereon, e.g. in the manner of a bayonet joint.

the bevel gear 12 meshes with a bevel gear 14 installed on a transverse spindle in the bearing case 7. This gear 14 is connected with spacing from its axis to a laterally acting link 15 whose other extremity is acted on by a thrust rod 16 which is axially displaceable in the bearing 7' and which at its outer extremity engages with a head 17 in,for example, the forceps branch 19 of the handle 20. The forceps handle 20 is pivotable aboutthe hinge pin 21 ofthe second forceps handle 22 fixedly joined to the housing 6. The pivotable handle 20 turns the bevel gears 14, 2 via the thrust rod 16, and thus also the rotary rod 4which closes the forceps jaws 2, 3 for tissue sampling and opensthesameforremoval of samples. The precise closed position oftheforceps jaws 2, 3 is established by the fact that the link 15 is placed in contact with an adjustable stop 23 upon actuatingtheforceps handles 19,20.

The forceps described is easy to keep clean and also to disinfect and sterilize.

Claims (10)

1. Surgical forceps comprising a housing; a forceps shaft having proximal and distal ends, the proximal end being secured to and projecting into the housing and the distal end having thereon a fixed cutting edge of a pair of forceps jaws; a rotary rod, extending axially through said shaft and having proximal and distal ends, its proximal end projecting from the shaft within the housing and its distal end having thereon a cutting edge rotatable with the rod to cooperate with the fixed cutting edge and form therewith a pair of forceps jaws; means within the housing for actuating the rotatable cutting edge by rotating the rod, said means including an axially displaceable thrust rod extending outwardly from the housing through a sealed bearing atthe proximal end ofthe housing; and a movable forceps handle connected to the thrust rod outside the housing to effect axial movement thereof to actuate the rotatable cutting edge.

2. Surgical forceps according to claim 1 wherein said cutting edge actuating means includes a pair of bevel gears meshing with one another, said gears being positioned at right angles to one another within the housing.

3. Surgical forceps according to claim 2, wherein the th rust rod is connected at its inner extremityto one of said bevel gears, which is rotatablyjournalled on a transverse spindle within the housing via a link acting laterally thereon, and at its outer extremity engages in a guided mannerwith a head in a longitudinal groove of said movable forceps handle.

4. Surgical forceps according to claim 2 or claim 3, wherein one of said bevel gears comprises a boss which has a hollow non-circular cross-section and is rotatablyjournalled, coaxiallywith the rotary rod, in a bearing at the distal end of the housing and wherein the proximal extremity of the rotary rod matches said non-circular cross-section and engages releasably in the boss.

5. Surgical forceps according to any preceding claim further comprising an inner bearing case within said housing providing said thrust rod bearing, said case also having a sealed bearing atthe distal end ofthe housing to accommodate the proximal end of the shaft and the rotary rod.

6. Surgical forceps according to claim 5, wherein the inner bearing case is open at least in its upper portion between the sealed bearings but is hermetically sealed off by the housing.

7. Surgical forceps according to any preceding claim, wherein the proximal ends of the shaft and the rotary rod are releasably retained in the housing by a removable cap at the distal end ofthe housing.

8. Surgical forceps according to claim 7, wherein said cap is screwed over the distal end ofthe housing.

9. Surgical forceps according to any preceding claim wherein the movable forceps handle is pivotally attached to a fixed handle mounted on said housing.

10. Surgical forceps substantially as herein described with reference to the accompanying drawings.