US 3842839 A
Description (OCR text may contain errors)
Ilnite States Patent [191 alis et a1.
[ 1 Oct. 22, 1974 1 RONGEUR  Inventors: Leonard Irving Malls, 219-44 Peck Ave., Hollis Hills, NY. 11423; Frank Macalus, 60 S. I-Iillcrest Ave., Ardsley, NY. 10502 221 Filed: Apr. 5, 1973 21 Appl. No.: 348,287
3,709,630 1/1973 Pohl et al 128/305 FOREIGN PATENTS OR APPLICATIONS 21,797 l/l893 Great Britain 128/318 24,791 3/1903 Great Britain 128/318 Primary Examiner-Channing L. Page Attorney, Agent, or FirmKeny0n & Kenyon Reilly Carr & Chapin  ABSTRACT A surgical instrument in the form of a power driven rongeur which includes an air turbine motor adapted to control the closing and opening of the cutting blades. A toggle linkage connects the cutting blades to a threaded member which linearly advances and retracts upon rotation of the air motor so as to cause the opening and closing of the cutting blades respectively.
3 Claims. 5 Drawimr Fiflnrne  References Cited UNITED STATES PATENTS 3,143,896 8/1964 Edwards 74/459 .llll
RONGEUR BACKGROUND OF THE INVENTION This invention relates generally to surgical instruments and more particularly to power driven rongeurs.
Bone removing or biting instruments called rongeurs have been used by neurosurgeons for a great many years. A number of different types have been available in different shapes of cutting blades and different sizes. Some have a simple plier like action in which the leverage provided for the cut is the ratio between the length of the instrument from the hinge point to the hand grip and from the hinge point to the cutting edge. Such an instrument may have a 6 or 8 to 1 ratio and usually has cup like blades with sharp edges so that the force in pounds exerted at the blades may be amplified from the 60 or 100 pounds of the surgeons grip to more than 500 pounds at the cutting blade, which is then distributed over the sharp edges providing a cutting force able to cut through a quarter of an inch of bone. Other rongeurs called double action rongeurs have an intermediate pair of joints and provide better control in a somewhat more favorable ratio. Nevertheless, the surgeon working with such rongeurs often is required to carry out more than an hour of hard physical labor just prior to beginning the most delicate part of his operative procedure.
One form of a power rongeur was introduced on the market several years ago. This particular system uses a rongeur operated by an air plunger or piston. For surgery this has the disadvantage that the stroke is swift and virtually unstoppable once it has begun. In addition, at the air pressures available the mechanical advantage is such that the cut is never at a power comparable to that which the surgeon can provide for himself so that the times when he needs it most, when faced with a very hard or heavy bone structure, he has to again return to hand rongeuring.
The power rongeur of this invention has neither of these major disadvantages. It is both completely controllable and higher powered than the surgeons hand rongeur.
SUMMARY OF THE INVENTION Briefly stated, the invention disclosed herein provides a power rongeur operated by finger pressure of the surgeon. A drive means in the form of an air turbine motor, operates a pair of cutting blades. A linkage, preferably a toggle linkage, has one end thereof connected to the cutting blades and the other end thereof to a threaded member. The threaded member is coupled to the rotary output of the air motor in a mannersuch that the threaded member is moved linearly upon rotation of the air motor. In this manner,,the cutting blades are caused to move with respect to one another.
The toggle linkage is pivotally connected to fixed supporting links which extend from the housing of the air motor. In this manner, the toggle linkage becomes substantially straight upon advancement of the threaded member so as to cause the cutting blades to close. When the toggle linkage forms an acute angle, caused by retraction of the threaded member, the cutting blades are open.
The threaded member is connected to the output shaft of the air motor by means of a coupling sleeve.
This sleeve includes at least a simulated portion of a thread or other suitable means for engaging the threaded member in order to cause the latter to move linearly upon rotation of the air motor.
In this manner, instead of the surgeon providing the power, the air turbine operating through the above linkages provides smooth powerful pressure of several times stronger than the surgeon can apply with his hands. The air turbine is controlled to close at a smooth rate and to stop in its closure at any point, and can be opened or closed by simply moving the control level backward or forward. The unit has been tested and has been found to do the job with safety, smoothness and speed with virtually no effort for the operator, while maintaining the total controllability required in a surgical instrument.
Accordingly, it is an object of this invention to provide an effective and efficient power driven rongeur.
It is another object of this invention to provide a power driven rongeur which provides a cutting force at least as great as that produced manually by the surgeon and is completely controllable during its entire movement.
These and other objects, advantages and features of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the power driven rongeur of this invention with the cutting blades in the open position;
FIG. 2 is a side elevation view of the power driven rongeur of this invention;
FIG. 3 is an enlarged plan view of the cutting blades in the closed position;
FIG. 4 is an enlarged end view, partly in cross section, taken along the line 44 of FIG. 1 illustrating the coupling between the sleeve and ball bearings; and
FIG. 5 is an enlarged side elevation view, partly in cross section, taken along the line 55 of FIG. .4.
DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawings, particularly FIGS. 1 and 2, the rongeur indicated generally at 10 is driven preferably by means of an air turbine type motor 11. Such a motor eliminates the danger of electric sparks as well as certain of the autoclaving problems associated with electrical motors. One suitable type of motor is illustrated in US. Pat. No. 3,574,374 issued on Apr. 13, 1971, although others may be substituted.
Air motor 11 is connected to an available source of air by means of the air hose l2. Lever 13 actuates the air motor 11 by means of the gearing 14 which in turn operates a 4 way air valve 15.
Support links 16 and 17 are pivotally fastened at one end to the motor housing and have pivotally attached at the other end a toggle type linkage. The toggle linkage includes links 18 and 19 which at one end are pivotally attached to the cutting blades 20. Links 21 and 22 provide a pivotal connection with threaded member Air motor 11 includes a rotary output shaft 25 which is coupled to the threaded member 24 by means of the sleeve 26. Sleeve 26 is fixedly attached to shaft 25 by means of a pin 25a. The bore of sleeve 26 is adapted to accommodate threaded member 24 and forms a ball bearing nut and screw combination. In this connection, sleeve 26 includes 2 apertures 27 (FIG. 4) where a connecting tube 28 enters. The tube 28 permits circulation of a number of steel balls 29 of such a size that they engage the threaded member 24 and pass through the aperture of tube 28. Thus, a highly efficient ball bearing nut and screw combination is provided. Alternatively, a standard threaded sleeve and a mating screw could be used, but would have high friction giving low cutting forces. Tube 28 is fixed to the screw by means of the mounting strap 30.
Operation of the power rongeur of this invention is illustrated in FIGS. 1 and 3. Cutting blades 20 are in FIG. 1 illustrated open and the threaded member 24 is retracted. Also, links 21 and 22 form an acute angle with one another. In order to close the cutting blades 20, the lever 13 is depressed which causes the air motor to drive the output shaft 25 and through the ball-screw arrangement advances threaded member 24. This in turn causes the toggle linkage to substantially straighten and close the cutting blades.
Thus there has been described an effective and efficient power driven rongeur. Additionally, the cutting force produced at the blades 20 is at least as great as that produced manually by the surgeon. Further, usage of an air motor such as described allows for complete control of the cutting action and allows for instant reversal simply by reversing the direction of the actuating lever 13. The air motor allows the cutting blades to close at a smooth rate and also to stop the closure at any point unlike the prior art.
Although the above description is directed at a preferred embodiment of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art and, therefore, may be made without departing from the spirit and scope of the present invention.
What is claimed is:
1. A power driven rongeur which comprises:
a. a rotary drive motor having an output shaft at one end thereof;
b. means for actuating said rotary drive motor;
0. a pair of cooperative blades comprising:
1. elongated members pivoted together intermediate their ends and 2. a pair of cutting blades at one end of the members;
d. linkage means having one end thereof connected to the other ends of the elongated members opposite said pair of cutting blades;
e. an externally threaded member having one end thereof connected to the other end of said linkage means;
f. an internally threaded member coupling the output shaft of said drive motor to said threaded member and having at least one thread thereof oppositely disposed to said threaded member to form a helical groove; and
g. a train of balls disposed in the helical groove provided by said externally and internally threaded members so as to provide linear movement of said threaded member upon rotation of said drive motor whereby said cutting blades are caused to move with respect to one another.
2. A power driven rongeur in accordance with claim 1 wherein said rotary drive motor comprises an air powered turbine type motor.
3. A power driven rongeur in accordance with claim 1 wherein said linkage means comprises pivotally mounted supporting links extending from said drive motor and a toggle linkage being adapted to take a substantially straight position upon advancement of said threaded member so as to cause said cutting blades to close.