DE9117265U1 - Surgical cutting instrument - Google Patents

Description

KorosOll : : .'8/ Hal &Igr;99&iacgr; Who!

Surgical cutting instrument

The invention relates to a surgical cutting instrument according to the preamble of claim 1. 5

The instrument is used as a medical or laboratory device, as a fixed apparatus, as a tool for medical or laboratory use, or as a surgical forceps. The cutting instrument can also be used as an orthopedic cutting device, as a resection device, or as a clamping forceps, as a hollowing forceps and as an instrument for removing tiny bone fragments; the forceps have jaws that are pre-tensioned towards their open or closed positions. The forceps can have a

Jaw construction, a hinge or snap-in construction 15

It may be or contain a tubular scraper member.

A known surgical cutting instrument according to Fig. 1 is a hand-held device that is held by the surgeon during surgical use. It is generally referred to as a laminecto-

mie instrument, namely for removing vertebral parts. There is also a so-called KERRSION mucus remover, which has a shovel-like cutting head. There are probably about fifty different types of available

Cutting instruments. The different versions are the 2b

Result of different cutting tips, different cutting lengths, which usually range from 15 to 28 cm, and they can also have different handles and spring combinations. The most important thing is the close fit

Tip of the surgical instrument. The surgeon needs a 30

surgical instrument that can be used to remove calcifications, to remove a bone fragment and to help with uniting or setting bones. The surgical instrument is also generally used to take tissue samples for biopsies, such as to remove tissue parts.

len during the operation.

A common known surgical cutting instrument has an angled upright rear fixed handle part, which in the upper section changes into an integrated fixed shaft.

[- since, which extends from the upper section of the fixed handle in

horizontal direction. The distal end of the fixed shaft has a stationary cutting tip. Near the upper end, a second upright movable handle is connected to the area where the fixed handle joins the fixed shaft by a stud bolt. The connection acts as a fulcrum for the movable handle. The pair of handles present an inverted V-shape in profile. There is a movable shaft that rests above the fixed shaft. The distal end of the movable shaft also has a cutting tip, its end facing the user’s body or its end facing the user’s body. 5

The end closest to the body is in contact with the upper side of the movable

The pair of shafts has a tongue or a corresponding groove section so that both parts are slidably connected to each other. The tongue-groove connection allows the movable shaft to be above the &Lgr; U

fixed shaft. A tension spring with an inverted V-shape is arranged between the two handles to keep them sufficiently open and at the same time to keep the two cutting tips at the tips of the shafts open. The

Spring creates resistance and gives the surgeon a 25

Tactile sensation when using the cutting instrument

tightens or loosens his grip on the handles. When the handles are pressed together, the upper end of the movable handle presses against the end of the movable shaft closest to the body. This causes the moving cutting tip 30

on the movable shaft against the fixed cutting tip on the fixed shaft. The upper cutting area between the two tips is located where the surgeon wants to remove material. Any material present in the cutting area

Material is cut as a result of the force against the fixed cutting tip 35

cut or punched out by the moving cutting tip when the surgeon presses the handles together.

The fixed cutting tip can have many configurations. Usually it is curved upwards or downwards and often bevelled. The circumference of the tip, which extends from the shaft

._ extends out, forms a semicircular profile with a diameter &ogr;

from 3 to 5 mm. This area within the circumference generally has a recessed cavity to receive the cut piece of bone or tissue. The movable cutting tip has a beveled edge with a flat or recessed front surface. The two tips form corresponding front surfaces and edges so that the surgeon can make a clean cut.

During the operation, the surgeon has a number of

surgical instruments with different tips and 15

sizes that he can use if necessary. The type of tip cannot be changed on known surgical cutting instruments, nor can it be removed after use for cleaning purposes or to replace defective parts.

be taken apart.
20

The worst disadvantage of a standard surgical cutting instrument is the frequency of broken tips. A broken tip renders the surgical instrument worthless. It

cannot be replaced economically and will be 25

usually thrown away. An important goal for almost all surgical instruments is to have a narrow cutting tip, commonly referred to as a small foot plate. Surgeons want narrow tips because they are easier to

work and this is the 30

Minimize injury. A typical surgical cutting instrument is designed to withstand 500 pounds (225 kg) of force or stretch at the tip before breaking. When the surgeon manipulates the handle and the handles

against each other, the pressure force is divided by the lever arm of the 35

movable arm, which presses against the end of the movable shaft closest to the body.

The movable cutting tip is caused to press against the stationary tip in response to the grip being squeezed by the surgeon. The stationary tip must be able to withstand the force of the movable tip pressing against it during the shearing and cutting process. If the force generated by the surgeon exceeds the designed limits, then the fixed tip or shaft will bend or break. The surgeon's requirement for a narrow base plate places limits on the structural strength and rigidity of the fixed shaft. Thus, breakage is very common when the handle is squeezed by the surgeon. Because of this disadvantage, replacement of expensive surgical cutting instruments and

from maintaining a larger supply of cutting tools-15

instruments with different peaks cause unnecessary expenses for hospitals, which have to be passed on to the patient.

The invention is based on the problem of creating a new surgical cutting instrument that meets the above-mentioned 20

Avoids disadvantages of known instruments.

This instrument should allow the insertion of different tips and also allow disassembly for cleaning purposes

and to replace defective parts.
25

The object is achieved according to the invention by the features of the characterizing part of claim 1. Further embodiments of the invention are protected in the dependent claims.

The subject matter of the invention is generally referred to as a surgical instrument or "rongeur", which is a forceps-like surgical instrument for removing calcifications,

to remove bone fragments or to obtain tissue fragments for biopsy purposes 35

to be removed. The subject matter of the invention contains a frame,

a slide mounted within the frame in a horizontal slotted channel, a fixed handle as part of the frame at its rear end, a movable lever handle connected to a

arm which extends from the lower middle section of the 5

frame, preferably a combined cover for a socket and a chamber, and a two-piece shaft with a cutting tip. The socket section is hinged to the front section of the carriage. The combined cover for socket and chamber can be unlocked and the two-piece shaft can be easily removed from the socket and reinserted. Different types of two-piece shafts are interchangeable in the socket of the same surgical instrument.

The two-part or two-piece shaft can be further defined as a structure with a fixed shaft, a movable shaft, a movable and a fixed cutting tip at its distal end, and with a star wheel at its

end closest to the body, i.e. facing the user. The distal 20

The end where the cutting tips of the movable and fixed shafts form a gap is called the cheek area or cutting area. The distal end of the combined shaft is known in the surgical industry as the foot plate.

It is always the aim of a manufacturer of a surgical cutting instrument to provide a small or narrow foot plate in his instruments. The surgeon requires a small foot plate because with such a cutting instrument

can work more easily and because a small footplate smaller 30

parts of a bone or tissue. The biggest disadvantage of a small footplate is that when the cutting tip of the movable shaft and the tip of the fixed shaft come together to cut off a piece of bone, the pressure exerted by the surgeon when pressing the

Handling the cutting instrument can occasionally lead to permanent deformation or fracture of the footplate area

which results in the destruction of the cutting instrument, which can no longer be used and must therefore be thrown away. A small base plate means a compromise in terms of the strength and integrity of the tip due to metallurgical limitations. A small base plate forces the manufacturer to use less metal to keep everything in small dimensions.

_n The subject matter of the invention contains a tension limiting element which

automatically compensates for excessive pressure on the handles by the surgeon. By automatically compensating and correcting excessive pressure on the part of the surgeon, the integrity of the footplate is maintained so that it

is not deformed or breaks apart. The low-pressure 15

Compensating element includes a flexible tension spring disposed between the fixed handle and the movable handle at an angle to partially resist the compressive forces created by the surgeon's grip. The tension spring also causes the tips of the movable and fixed shafts to separate when the surgeon releases his grip. This then allows the surgeon to remove the material from the tip of the cutting instrument after the cut has been made. The high pressure compensating element is

a vertically arranged stiff spring, which with the inner edge 25

of the fixed handle. The stiff spring keeps the slide in position and stationary on the frame. The slide has the ability to move slightly in its horizontally arranged groove-shaped channel

within the frame backwards or forwards. The forward and 30

The sliding movement is very limited and is used to compensate for the surgeon if he presses the movable handle too close to the fixed handle. The slide can be moved within a very limited range

slide back and forth. The upper edge of the stiff spring presses 35

against a crossbar that extends downwards from the bottom of the carriage. The crossbar is against the back

of the carriage. The stiff spring biases the carriage with the bushing and shafts connected to it against the fixed handle. However, when sufficient force is exerted on the fixed handle by pressing the movable spittoon against the fixed spittoon, which is caused by pressing the upper part of the movable handle against the end with the ball of the movable shaft closest to the body, the stiff tension spring gives way and is slightly movable, allowing the carriage and shafts to move relative to the rigid frame and the integrally formed fixed handle. As a result, the surgeon can only exert enough force on the foot plate to cut off the bone part, regardless of how tightly he presses the handles together.

The subject of the invention provides for further new features. One feature enables the use of different types of foot plates, as the subject of the invention provides for interchangeable shaft pairs. The pair of fixed shaft

and movable shaft can be pulled out from the socket as a unit and quickly replaced with another new or different shaft with a different foot plate.

Another preferred embodiment or feature is that the shaft can be rotated about its axis by 45° to change the orientation of the foot plate in relation to the socket and thereby allow a greater range of variation in the use of the instrument by the surgeon.

For this purpose, a star wheel is provided on the end of the fixed shaft closest to the body, i.e. the end facing the surgeon, and a locking element that prevents the shaft from twisting when the cover for the socket and chamber is closed. The surgeon simply presses a quick release he

down, press the tip to the desired angle and

then releases the lever again, locking the shaft and tip in their new radial angles. The end of the movable shaft closest to the body has a spherical

projection that fits into a socket-like recess on the 5

top of the movable handle. The movable shaft slides along the flat top of the fixed shaft in response to the surgeon squeezing and moving the movable handle toward the fixed handle.

The frame has an arm that extends from below the center section where the movable handle is attached to it. This is the fulcrum or pivot point for the movable handle, allowing it to move about this point

The distance from the bottom of the handle to 15

to the fulcrum is approximately twice as large as the distance from the fulcrum to the socket-like recess on the top of the handle. The leverage effect exerted by the handle when it is pressed against the other handle

exerted force results in a considerably greater force on the 20

Ball end of the movable shaft. This multiplied force is transferred to the movable cutting tip and causes it to press hard against the fixed tip or a bone that is in the cutting area of the tip.

A section of the two-piece shaft near the end of the socket closest to the body, i.e. the end facing the surgeon, forms a half cylinder, while an elongated rectangular central channel is formed in the upper flat side of the hemispherical cylinder of the fixed shaft. The movable shaft following

this section has a rectangular cross-section and slides back and forth in the rectangular channel cut out in the flat top of the fixed shaft. This interaction between the movable shaft and the fixed shaft changes towards the end of the cutting tip, with a

Dovetail joint is formed where the fixed shaft has a groove with the shape of an inverted V, while the

movable shaft has a tongue with a corresponding V-shape. This dovetail-shaped movable sliding connection prevents the tip of the movable shaft from separating from the

Festivity.
5

There are other preferred embodiments of the invention, such as a locking trigger mounted to the rear of the instrument. The trigger is spring loaded so that the combined cover for the socket and chamber is held in the locking position and does not open until the trigger is depressed. A pair of quick release levers can be mounted to the left and right sides of the socket. The release levers can be depressed to allow the shaft to rotate within the 5

bushing. A flat spring may be provided on the top of the movable carriage which maintains pressure on the locking device pivotally connected to the carriage so that the star wheel cannot rotate until the quick release button is depressed.

Embodiments of the invention are shown in the drawing. It shows:

Fig. 1 a left side view of a bone cutting device or 25

State-of-the-art punching machine manufactured in Europe and known as the Eberhardt machine,

Fig. 2 is a side view of an embodiment of the invention,
30

Fig. 3 is a plan view in the direction of line 3-3 of Fig. 2,

Fig. 4 is a full longitudinal section taken along line 4-4 of Fig.

3, with the jaws or cutting tips in full open 35

Position and the movable and fixed handle are shown in the fully open resting position before a bone

piece is cut off, thus showing the first stage of cutting out a piece of bone,

Fig. 5 is a longitudinal section similar to that shown in Fig. 4, showing the cutting tips in intermediate position and during the process of cutting out a piece of bone, with the movable handle shown in the intermediate closing position, thus showing an intermediate stage of the bone cutting out process.

shows,

Fig. 6 is a longitudinal section similar to those of Fig. 4 and Fig. 5, namely the last stage of the bone excision process,

Fig. 6 A is a longitudinal section similar to that of Fig. 6 using a different stiff tension limiting spring and an additional horizontal spiral spring or so-called BELLEVILLE spring,

Fig. 7 is a cross-sectional view taken along line 7-7 of Fig. 4 showing the connection between the inverted V-shaped tongue and groove in the distal portion of the fixed and movable shaft,

Fig. 8 is a cross-section along line 8-8 of Fig. 4 showing the continuous connection between the right-angled tongue and groove,

Fig. 9 is a longitudinal section along the line 9-9 of Fig. 4 showing the internal components of the subject invention,

Fig. 10 is a cross-section along the line 10 - 10 of Fig. 9 to 35

Representation of the star wheel on the fixed shaft,

Fig. 11 is a view similar to that shown in Fig. 10 for

Representation of the two-piece shaft, with the radial angular alignment compared to the representation in Fig.

_. 10 is rotated 90 clockwise, resulting in a

Change in the radial angle alignment of the cutting tip by 90,

Fig. 12 is a partial section of the circle shown in Fig. 11 to show the cutting tips at the ends of both the movable and fixed shafts,

Fig. 13 is a partial plan view of a preferred example of cutting tips according to line 13 - 13 of Fig. 12,

Fig. 14 is a partially sectioned partial view of another

Example of a tip of the fixed part or the fixed tip,

Fig. 15 is a partial plan view taken along line 15 - 15 of Fig. &Lgr; U

14,

Fig. 16 a partial longitudinal section of a further embodiment, in which a pivotable jaw blade member

to the tip of the movable member in the form of the 25

shaft is attached,

Fig. 17 is a partial plan view taken along line 17 - 17 of Fig. 16 showing the tip of the pivotable jaw blade member,

Fig. 18 is a longitudinal section similar to that of Fig. 16 showing the pivotable jaw blade member in the open position,

Fig. 19 unlocking the socket by pressing the trigger and easy and quick removal of the pair of fixed and movable shaft from the socket

and reinserting it into the socket after disconnection 5

and cleaning the shafts,

Fig. 20 the separation of the fixed and the movable shaft from each other.

The invention is explained in more detail below using the exemplary embodiments. Figures 2 and 3 show a side view and a top view of an object of the invention in an operational state. Here, the fixed handle 10 is made in one piece with

the frame 15 or integrated with it; furthermore 15

a movable handle 20, an openable and closable socket 25 are shown; the movable shaft 30 and the fixed shaft 35 extend from the socket 25; a flexible tension spring 40 is provided to hold the movable handle 20 in the fully extended position, furthermore a rigid

Spring-loaded limiting element 50 connected to the inner edge of the fixed handle 10, a trigger 60, a pair of trigger legs 65 on each outer side of the cover 27, and a movable carriage 70 which is mounted in a slotted channel 71 within

of the frame 15 is provided.
25

The movable carriage 70 is discussed in more detail below together with the rigid frame 15 in which the carriage is slidably mounted or mounted. Figures 4, 5, 6 and 10

show the slide 70 in a larger view. The fixed handle 10 30

is aligned vertically, with the thumb grip 11

horizontally as a balance of the frame. The fixed handle 10 and the frame are manufactured as a one-piece unit. The cross-section of the carriage 70 has an inverted T-shape as shown in Fig. 10 and slides in a 35

Cavity forwards and backwards, such as an inverted T-shaped channel 71 formed in the frame 15. The front end of the

The slide 70 has a transverse opening through which a pin 75 passes for pivotally mounting the bushing 25 with the slide 70. The bushing 25 can be unlocked by turning this pin 75, which is connected to the end of the slide 70. The other end of the slide adjacent to the inner edge 52 of the fixed handle 10 has a transverse shoulder 78 that extends downwards. This shoulder 78 abuts against the upper inner edge of the fixed handle.

The rigid spring 50 is arranged vertically, its lower edge is connected to the inner edge 52 of the fixed handle by a screw 53. The upper edge of the rigid spring 50 strikes against the shoulder 78 of the slide. The rigid spring exerts a

, ,. Counter pressure on the shoulder and thus on the slide in order to

to keep it pressed against the inner edge 53 of the fixed handle. As a result, the carriage is always fixed and in this position unless extreme forces are applied to the handles by the user such as the surgeon during use. If the surgeon, when pressing the movable handle 20 against the fixed handle 10, exceeds the threshold &eegr; force at the cutting tips, which is determined by the stiffness of the rigid spring, the carriage 70 begins to slide away from the fixed handle, along the bushing 25 and the cover 27, as well as along the shafts 30

and 35. The stiff spring 50 is a safety device because 25

the tip 31 of the movable shaft 30, which presses against the tip 36 of the fixed shaft 35, then forces both shafts as well as the bushing and the cover and the carriage to move away from the fixed handle 10 when the upper part of the handle 20, the

against the spherical end 90 of the movable shaft 30 3U

presses firmly enough against the ball.

Fig. 6 A shows a modification of the previously described rigid spring. Here, the shoulder of the slide is supported by a

Transverse groove 102 replaced, into which the upper end edge of the modified-35

ten stiff spring 100 is embedded. There is an additional horizontal cavity 104 within the frame for holding a

further spring 108 and a horizontal rod 106, the cavity 104 extending below the carriage. The spring 108 can be a conventional spiral spring or a series of so- called BELLEVILLE disc springs.

The horizontal rod 106 is part of the carriage and extends from the base thereof. The rod centers and holds the compressible compression spring so that the spring assembly compresses the _1Ω carriage and acts as a resistance to the carriage moving to the left in the frame. The area of the carriage where the rod is attached is the surface that presses against the end of the spring assembly and compresses it within the cavity as the carriage moves.

, -. moved to the left within the frame. Fig. 6 A shows the

Carriage approximately at its maximum leftward movement caused by over-squeezing of the handles by the surgeon while using the cutting instrument during surgery. The rigid spring means 100 and the compressible spring 104 cooperate to resist the movement of the carriage. Both springs provide a more gradual threshold resistance to allow the carriage to move in response to over-squeezing.

There is another tension spring 40, one end 42 of which is connected to the inner edge 52 of the fixed handle 10 via a screw 43. The spring 40 has a roller 44 which is connected to its other free end and is located in a small recess 21 on

the inner edge of the movable handle 20. The 30

The purpose of this tension spring 40 is to keep the movable handle 20 at a certain distance from the fixed handle 10 when the invention is in the rest position, in which the tips 31 and 36 of the shafts are also in the open rest position. This area is referred to as the cutting area of the instrument. When the surgeon presses the handles together, this

additional tension spring 40 also acts as a resistance to prevent the surgeon from pressing down too hard when removing a portion of bone or the like. The spring also provides a tactile feeler for the instrument such that the handles are spread apart when the surgeon releases his grip. It also opens the cutting area to allow removal of the tissue sample or the like.

..” The upper portion of the movable handle 20 is pivotally mounted on an arm 120 extending from below the frame in the central region thereof. The arm or mounting point is integrally formed with the frame. The upper end of the movable handle 20 has a rounded recess or socket 122 which is engaged with the end 90 of the ball

of the movable shaft 30. The ball-shaped head 90 at the end of the movable shaft 30 closest to the body, i.e. facing the surgeon, is connected to the rounded recess 122 on the top of the movable handle 20 so that the rounded recess 122 presses against the ball 90 and causes the movable shaft 30 to press against the tip 36 of the fixed shaft 35 and close the cutting area and thus remove a portion of the bone or tissue for biopsy purposes when the movable handle 20

pressed and around its fulcrum on the mounting arm 120 25

which extends below the frame. The movable shaft 30 moves back and forth or backwards and forwards in relation to the fixed shaft. The fixed shaft 35 has a bevelled semi-cylindrical shape. The body-proximal

The end of the fixed shaft facing the surgeon has a 30

spur-shaped or star-shaped wheel 130 connected thereto, while the distal end has a bevelled tip 36. The tip 31 on the movable shaft also has a bevelled cutting surface, with a pressure relief opening

or a tunnel 32 to prevent the escape of tissue or 35

Figures 12 and 13 show this type of tip. Figures 14 and 15 show a modified

Version of a tip, where the tip is 140 upright and a

cap 142. The tip 144 of the movable shaft has a corresponding shape to fit into the cap 142. The p. Figures 16 to 17 show a tip with jaws and scoop for

Removal of a larger amount of tissue. The tip 150 on the movable shaft 155 is pivotally connected to the fixed shaft 165. The tip 160 of the fixed shaft forms the lower half of the scoop.

Shafts 30 and 35 will now be discussed in more detail.

Both are clearly shown in Fig. 20. The movable shaft 30, which is longitudinally movable back and forth on the top of the fixed shaft 35, also has a bevelled

semi-cylindrical shape, as shown in Fig. 8. The shaft has 15

a right-angled end piece 170 which terminates at its proximal, namely the rear end facing the user, end with a small button or ball 90. The distal end has a tongue portion 172 which extends approximately 5.1 cm from the end. The tongue portion 172 fits with a

Groove section 174 which is cut into the flat or narrow top of the fixed shaft 35 so that the tongue and groove form a dovetail joint in the cross section according to Fig. 7 to form a locking rail and the

distal end of the movable shaft at a detachment from the 25

fixed shaft end when the instrument is in use. The end of the movable shaft closest to the body, facing the surgeon, slides within a rectangular groove where the rectangular section 170 is located

176, which extends along the longitudinal axis of the fixed shaft in the direction of 30

to its proximal end, back and forth.

The star wheel has a radial groove for receiving and holding the rectangular section 170. The shafts can be made of metal or plastic.

The bushing 25 is formed in one piece with the cover 27 for the chamber. It is hollowed out and has a cylindrical bore to facilitate the insertion of the two-piece shaft into the

,- socket. The shafts then extend partially

or divided away from the bushing 25. The cylindrical bore which holds the section of the shaft closest to the body, facing the surgeon, has a circular cross-section. It also forms a conical recess 26 (Fig. 3, 4 and 9), whereby

_n the inner chamber of the cover converges against the bore.

The end of the fixed shaft closest to the body, which has the star wheel 130 connected to it, slides into the conical section 26 of the bushing so that it can only expand a certain section and then stop. The

Star wheel 130 arranged in a conically bevelled section results in 15

a firm fit of the proximal end of the fixed shaft in the socket. For all practical purposes or applications, the fixed section of the shaft remains fixed in relation to the socket 25 when the instrument is in use. When the

movable handle, the upper end of the handle, the 20

mates with the spherical end 90 of the movable shaft, against the movable shaft 30 and presses it in the direction of opening the sleeve 25 and away from it. This slight movement causes the distal tip 31 of the movable

shaft, towards the distal tip 36 of the fixed 25

shaft, closing the jaw area and capturing a piece of bone or tissue in the jaw area or cutting area.

The combination of fixed shaft 35 and star wheel 130 allows 30

the surgeon a great deal of flexibility by allowing him to rotate the shaft around its axis at 45° angles either clockwise or counterclockwise, in order to adjust the angular alignment of the footplate to the distal

ends of the shafts. The orientation of the tip of the 35

shaft can be changed by pressing down the quick release side lever 65, which engages the lock 66 on the star wheel

130 and the shaft to rotate both as a unit. This allows the surgeon to change the orientation of the cutting tips without opening the socket and cover.

,- simply pressing the lever 65 the shaft combination can be

clockwise or counterclockwise in 45° increments or quarter turn increments to change the angular orientation of the cutting area. Another feature of the shaft is that the two-piece shaft unit can be quickly and easily removed from the instrument, cleaned, sterilized, returned together and reinserted into the instrument. A different shaft unit can also be used if desired. The shaft is removed by first removing the

Press down the shutter release 60 on the back of the frame so that 15

the socket can be unlocked by pivoting the shaft downwards in relation to its fulcrum, which is attached to the front section of the slide 70. By unlocking the socket, the shaft can be pushed backwards out of the socket and the protruding end closest to the body can be pushed through the cover

This is clearly shown in Fig. 19. The shaft assembly can only be removed in this way because the star wheel 130 prevents the shaft from being removed from the front of the bushing bore.

A narrow flat spring 68 is provided, one end of which is bolted to the top of the carriage 70. The free end of the flat or leaf spring presses against the lock 66, which in turn prevents the star wheel 130 from freely rotating.

The lock is on the top of the slide 30

and pivotally mounted between a pair of supports or posts 69. The distal end of the lock contains a sawtooth that mates with the V-shaped recesses 131 on the star wheel 130 to prevent the star wheel from rotating.

prevent, as long as the tension of the flat spring 68 35

The stress relief is achieved by pressing down a

of the quick release buttons 65 located on each side of the sleeve and cover. The button 65 allows the star wheel 130 and the shafts 30, 35 to rotate to the angular orientation selected by the surgeon.

The rear portion of the slide includes an open horizontal positioning groove 180 cut into the end with a cross pin 182 positioned between the frame and through the groove within the slide so that the slide can only move a limited amount within its channel. The base of the trigger 60 is also connected to the top of the slide and a groove extending vertically adjacent to the top of the fixed handle has a

Spiral spring 59 is provided. The spring presses against the trigger, 15

to hold it in the locked position and the only way to release the trigger is to depress the knurled portion of the trigger to release the trigger, which is pivotally attached to the top of the slide and

This allows the socket and the cover to be inserted into a 20

to be pivoted into the open position to access the inner chamber and to remove the shaft.

Claims (4)

KorosOll 8 May 1991 Bm/ho ■ enclaims c 1. Surgical cutting instrument, marked - by a frame (15) having a front section, a middle section, a rear section and a channel, - by a fixed handle (10) which is integrally formed with the rear portion of the frame (15) or firmly connected ,Q and extends downwards from this rear section extends, - by an arm and by a slot in the central section of the frame (15), - by a movable handle (20) which is pivotally connected to the , ,_ front section of the frame (15) is attached to the arm, wherein the end of the movable handle closest to the body, facing the surgeon, extends upwards and through the slot of the frame (15), - by a bushing (25) attached to the frame (15), - and by a two-piece shaft (30, 35) extending from A L) the sleeve (25) to remove a portion of bone or tissue. 2. Instrument according to claim 1, characterized in that the Shaft consisting of a fixed shaft (35) and a movable 25 shaft (30). 3. Instrument according to claim 1 or 2, characterized - by a carriage (70) having a front section, a middle section and a rear section, which is slidably attached to a channel (71) of the frame (15), - by a rigid spring device (50), one end of which is attached to the frame (15) and the other end of which is detachably attached to the carriage (70), * ■ φ · - by an integrated or one-piece bushing and cover device (27) which is pivotally connected to the front section of the carriage (70), - by a star wheel (130) connected to the end of the fixed shaft (35) closest to the body, - by a locking device (66) attached to the carriage (70) to prevent the combination of the two shafts (30, 35) from rotating about its axis, - and by a quick release device (65) for releasing the locking device (66) which is attached to the slide (70), to allow the surgeon to quickly rotate the shaft combination and to adjust the angle of the tip at the distal 15 End of the combination of shafts (30, 35). 4. Instrument according to one of claims 1 to 3, characterized by a locking and releasing device (60) which is Frame (15) is attached,
20 to hold the bushing and cover device (27) in place during operation and to enable this device to be unlocked so that the combination of shafts (30, 35) can be removed from the instrument for quick replacement or cleaning purposes can be removed.
25