GB2027638A - Releasable connection of a surgical cutter blade support to a drive - Google Patents

Abstract

A toothed cutter is provided between a pair of side walls 22, 23 releasably connected with a gear housing 12 by a pair of studs 17, 18 on the housing engaging holes 33, 34 in the side wall 22 and by a screw and nut passing through aligned openings 19, 26 in the housing, the side walls and an intermediate layer 24. <IMAGE>

Description

SPECIFICATION Cutter, especially a surgical cutter The invention relates to a cutter, especially an operation cutter having a handle, a driving gear mounted on the handle, and extending from the front of the handle, a cutter attached to the driving gear casing and provided with two side walls between which there is provided a chain wheel for driving a toothed band cutter, and between which the side walls provide support for the band cutter.

Such a construction is described in the specification of German Patent Application No.

P. 26 11720.

The cutter described in this German application has the cutting member fixed with the gear structure.

The teeth of the band cutter can however wear away. It is also difficult to fulfil the requirements for freedom from germs, ability to sterilize and easy running, as small particles and fluids can .reach between the wheels, in the bearings and so forth.

The problem of the invention is to provide a solution by which fluids and small particles are no longer involved in such a manner and which enables as many parts as possible to be re-used.

According to the invention this problem is solved by the following features:~ (a) The cutter is a special, altogether exchangeable structural member which can be connected with the gear structure by means of a quick connection device.

(b) The cutter has one coupling part and the gear structure is provided with another coupling part which serves to transmit the rotary energy.

(c) By means of the quick connection device both coupling parts are engaged.

(d) An intermediate layer is provided in the space between the side walls at least in the effective region of the quick connection device.

Thereby one can make the handle and the gear casing as a single unit, which at the same time makes the knife cheaper. One can completely encase the gearing framework, so that only a square shaft extends to the exterior as the one coupling half, and retains therein fluid and parts of the gearing. One is also in the position to select different knives as appropriate and to be able to mount them on the same gearing framework. For example one can give to the knife band optimal toothing according to the cutting efficiency, or alternatively one can select a cutter in which the cutting elements are shaped in accordance with the particular related cutting problem.

As a quick connecting arrangement many known simple or complicated constructional parts can be used. Such a quick connecting arrangement can be a simple spring clamp, which one pushes open. It can also be a spring-loaded Uprofile element which one pushes open. Flap connections are possible. One can carry out the quick connection arrangement in two halves, of which one is arranged on the gearing structure and the other in the cutter. For example one can provide the one half as a mushroom-shaped part which can be located within a tapered hole. There are such connecting elements for example in the automobile industry for fixing the covering on the parts of the bodywork. The quick connecting arrangement can also be a threaded bolt with a nut, knuckle or wing nut.It is important that the quick connecting arrangement pulls or pushesathe cutter into the correct position on the gearing structure. The intermediate layer or spacer prevents the very thin cutting elements (which have a thickness in the region of one millimetre or less) from being distorted or jammed, which otherwise would result in a poor running of the cutter band, which would mean a higher current usage for the motor in the handle, which is a great disadvantage with battery drive, would lead to additional heating in the motor and load the gearing. Additionally one can shape the intermediate layer so that it is also the supporting or thrust position for the knife band so that wheels referred to in the main application are simply guided through the outer circumference of the intermediate layer.This intermediate layer also then has the advantage to reinforce the extraordinarily thin blades and otherwise prevents that fluid or parts can get into the middle region of the knife.

A special connecting device is provided for taking up a breaking load which balances both coupling halves whereby pressure is taken off the two coupling halves and especially the bending forces occurring during cutting.

A constructional form of the invention will now be described by way of example with reference to the accompanying drawings wherein:~ FIGURE 1 is a schematic plan of the cutter, however only showing the region of the gearing casing; FIGURE 2 is a view in the direction of the arrow A, however omitting the cutting edge; FIGURE 3 is a view in the direction of the arrow A, however without the handle gearing frame and the under cutting wall.

A motor is provided in the handle 1 The output shaft of the motor transmits its rotary energy into a completely enclosed gearing structure 12. The structure 12 extends to the left of the handle 1 1 and is connected to it in a fixed manner and if desired in a fluid tight and sterilisable manner. In the gearing structure 12, the rotary energy, speed, torque, and direction is converted and transmitted through a plane wall 13 of the gearing structure 12 by means of a square ended spindle 14 which is mounted rotatably by a bearing in a collar 16. As shown in Figure 2 to the right of the square end 14 above and below, two vertically located studs 17, 18 are provided which are fixed to the wall 13. A hole 19 extends through the left hand end of the casing 12 but this hole does not communicate with the inside of the gear structure 12.

A cutter 21 has a rear cutting wall 22, a front cutting wall 23 and an intermediate layer 24 occupying the narrow parallel space between the walls 22, 23. The cutting walls 22, 23 and the intermediate layer 24 are fixed together. A hole 26 extends through the walls 22,23 and layer 24 and in its mounted condition is continuous with the hole 19. The layer 24 is disposed within the contour of the walls 22, 23. The upper run of a band cutter (not shown) is carried on the upper surface 29 and a lower frontal surface 28 serves as a support for the band cutter. At the right the 'syer 24 is spaced from a sector 29 where a chain wheel 31 can run which drives the band cutter. The teeth (not shown) of the chain wheel enter between the chain links of the band cutter.

The bearing of the chain wheel 31 between the walls 22, 23 is not shown. For example, collars can be provided on opposite sides of the chain wheel 23 having bearings in the walls 22, 23. The chain wheel 31 has a square hole 32 in which the square end 14 is engaged.

The cutter wall 22 has on the right two fitting holes 33, 34 in which the studs 17, 18 engage.

A screw-nut device can for example be provided in the holes 19, 26. In the region, however, a pressure-knob kind of connection or a cross-bar or the like could be provided in place of these holes by which a connection can be made quickly. By such a connection the cutter 21 is resistant to breaking load not only in the rear region of the gear structure 12 but is balanced together with the studs 17, 18, the square end 14 and the square hole 32.

Claims (3)

1. A cutter, especially an operation cutter having a handle, a driving gear mounted on the handle and extending from the front of the handle, a cutter attached to the driving gear structure and provided with two side walls between which there is provided a chain wheel for driving a toothed band cutter, and between which the side walls provide support for the band cutter characterized by the following features:- (a) The cutter is a special, altogether exchangeable structural member which can be connected with the gear structure by means of a quick connection device.

(b) The cutter has one coupling part and the gear structure is provided with another coupling part which serves to transmit the rotary energy.

(c) By means of the quick connection device -both coupling parts are engaged.

(d) An intermediate layer is provided in the space between the side walls at least in the effective region of the quick connection device.

2. A cutter according to claim 1 characterized by a special connecting device is provided for taking up breaking load which balances both coupling parts.

3. A cutter substantially as described with reference to the accompanying drawings.