Surgical Drill With Detachable Hand-piece

Abstract

A drive housing has a drive shaft having a drive clutch extending therefrom. A detachable hand-piece includes a compound driven shaft with a gear and pinion arrangement between forward and intermediate shaft members. The intermediate shaft member includes a claw which has extending arms which mate with cooperating notches in a clutch member attached to said drive shaft. The operative engagement is effective to drive a cutting element connectable to the forward shaft by means of a split shaft-collet arrangement and an operative engagement can be effected while the motor is turning. An operative engagement can also be effected with the hand-piece at an angular disposition to the drive housing.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a surgical drill having a detachable hand-piece.

Many surgical procedures require the use of drilling implements for several applications, such as drilling holes in various bones. High speed drills, generally driven by air motors, have been in use for some time, but their performance leaves something to be desired.

Specifically, prior art drills have generally utilized a standard chuck arrangement to connect a cutting element to a drive shaft. Such arrangements create a problem of centration of the cutting element. It should be appreciated that an uncentered cutting element will produce a larger hole than is wanted, a characteristic that is extremely undesirable in most surgical procedures.

It is evident that the elapsed time of an operation can be a critical factor in the success of a particular operation. Prior art drills have been found wanting, in that, to change a cutting element, as is often necessary, the drill must be switched off, the chuck opened, a new cutting element centrally inserted in the chuck, the chuck closed and then the drill must be switched on. These steps must occupy the attention of at least one person in the operating room and render the drill inoperative for a substantial and perhaps critical time. During this time a surgical wound may remain open without any positive surgery being completed.

The present invention is designed to fill the obvious gaps present in the prior art. The drill embodied in the instant invention need not be shut-off to effect a cutting element change. Detachable hand-pieces each include their own cutting elements and are connectable to a drive means while the drive shaft thereof is rotating. In this manner very little precious time changing cutting elements is lost during an operation. However, bearing arrangements in the hand-piece insures accurate centration of the cutting element at all times.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a surgical drill which permits the simple interchange of hand-pieces while the drive motor is operating.

Another object of the present invention is to provide a surgical drill in which the cutting elements are constantly centered.

Still another object of the instant invention is the provision of a surgical drill in which the cutting elements are easily interchanged.

In accordance with the above designs the surgical drill embodying the present invention includes an air drive motor and a drive shaft mounted in a housing. The air motor and drive shaft housing are connected by means of a tubular connector having one inlet passage and two exhaust passages, and the connector hangs from the underside of the drive housing.

A detachable hand-piece includes a housing with a nozzle on one end, the other end being hollow for coupling to the drive shaft housing.

The hand-piece includes a compound shaft on the front end of which the cutting element is attached. This is effected by splitting the forward end of the driven shaft and forming an opening therein for the reception of the shank of the cutting element. A collect-type fitting fits over the split shaft, threadedly engaging therewith to lock the shank in the driven shaft.

The driven shaft is a compound shaft consisting of a forward shaft member to which the cutting element is attached and an intermediate shaft member which couples to the drive shaft. The joinder between the forward and intermediate shaft members is effected by the provision of a gear on the intermediate member and a pinion on the forward member. This type of connection permits the angular disposition of the forward and intermediate shaft members. In this joinder only a few of the teeth on the gear and pinion are in contact at a particular instant, but the contact is sufficient to maintain a driving connection.

The intermediate shaft member is coupled to the drive shaft by means of a claw member attached at the distal or rearward end thereof. That claw member comprises arms which extend outwardly therefrom toward said drive shaft. The drive shaft includes a clutch member which has cooperating notches, which notches are clutched by the arms upon coupling. This structure permits coupling while the drive shaft is rotating. In effect the arms contact the clutch member and slide therealong until they are received in the notches.

The drive shaft includes a housing which has a ring rotatably received in a groove therein. The housing is pressfittedly received within the hollow end of the hand-piece housing and the ring permits the rather effortless coupling and removal of hand-pieces.

The above and other objects of the present invention will be apparent as the description continues and when read in conjunction with the appended drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1, is a partially cut-away plan view of a preferred, straight shaft, embodiment of the present invention.

FIG. 2, is a partially cut-away plan view of an angular hand-piece.

FIG. 3, is a partial plan view of the drive shaft and its housing.

FIG. 4, is an enlarged isolation view, partly in cross-section, of a preferred structure for the attachment of cutting elements.

DETAILED DESCRIPTION

According to FIGS. 1 and 2 the present invention, in a preferred embodiment, comprises a hand-piece 10 which includes the rear housing 12. An intermediate shaft member 14 is rotatably mounted in housing 12. At the forward-most end 16 of intermediate shaft 14 is the gear 18 having teeth 20 the function of which will be apparent as the description continues.

The hand-piece 10 includes the forward section 30 which includes the front housing 32 which is knurled 34 for dependable grasping by a surgeon. Rotatably mounted in the housing 32 is the forward shaft member 36. That shaft member is kept at constant center by way of the bearing means 38 and 40 which can be of any general configuration, but a preferred choice is a ball bearing with inner 40a and outer 40b races, and ball bearings 40c centrally therein. The provision of two sets of bearings 40 in the front of housing 32 insures constant centration as they will compensate for each other if one is thrown out of alignment. An arrangement of retainer rings and springs variously positioned about the bearings 38 and 40 maintains those bearings at the proper position. Similar sets of bearings 41 are arranged about the intermediate shaft 14 and maintain that shaft at constant center. It should be evident that in most surgical procedures, the feature of constant centration is exceedingly desirable.

The forward-most part of housing 32 includes a head-piece of nozzle 42 having a central opening 44 therein for the reception therethrough of a cutting element 46. The cutting element 46 comprises a cutting head 48 which is in all respects a conventional cutter and a shank 50 which is received in the central bore 44. One manner of attaching the cutting element 46 to the forward shaft member 36 is by having a central bore 52 in that shaft and suitably locking that shank therein. A more detailed description of a preferred shank locking arrangement will be discussed in conjunction with a description of FIG. 4.

The rearward end 60 of shaft 36 includes a pinion 62 having teeth 64, generally identical in number and contour to the teeth 20. It is the gear 18-pinion 62 arrangement which provides the operative driving engagement between the forward and intermediate shafts 36, 14. It should be indicated at this point that the arrangement thus far described is the preferable manner of producing a long, slender drill. A single shaft would introduce the problems of flexing or bending thus destroying any centration produced by the bearings.

The front and rear housings 32, 12 are joined by means of the cylindrical fitting 72. That fitting 72 is threadedly joined to housing 12 and includes a groove 73 which surrounds and holds a rib 74 of housing 32. The fitting 72 can be removed from the respective housings by sufficient rotation for purposes of servicing or other adjustments.

The description of the drill thus far, is equally applicable to the embodiment of an angular front housing as shown in FIG. 2, as well as the linearly aligned housings illustrated in FIG. 1. The front housing 32 as shown in FIG. 2 has a knee or bend 80 in the vicinity of the gear and pinion 18, 62. In this arrangement it is evident that there can be no complete mesh between the teeth 18, 62. While only several teeth of the gear 18 and pinion 62 can mate at a particular instant this is sufficient to maintain an operative driving relation therebetween. This arrangement is particularly useful where it is desired to reach very inaccessible areas in the body during a sensitive operation.

Turning to FIG. 2, there is shown the drive means embodying the instant invention. A prime mover or motor 100 (not shown) is connected to a drive shaft housing 102. The prime mover can be any conventional type but an air motor exihibits operating characteristics most useful to the present invention. While not shown, an air motor contemplated by this invention would be of the type which sits on the floor and is operated by a foot pedal. A tubular connector preferably connected to the underside of the drive housing 102 so that the surgeon is better able to bear the weight thereof. The tubular connector comprises separate air inlet and exhaust passages and is releasably connected to the air motor by means of fittings thereon. For superior exhaust characteristics an additional exhaust conduit may be provided.

The specific linkage between the motor 100 and the handpiece 10 is illustrated in FIGS. 3 and 4. As shown in FIG. 3 a drive shaft 104 is centrally located within housing 102. On the forward end thereof is the clutch member 106 which has a pair of notches 108 (only one of which is illustrated). The front base or end 110 of the clutch member 106 is curvilinear in shape the purpose of which will be evident as the description continues. Protruding from the base 110 is the guide member 112 which, as will be hereinafter described, insures that the drive shaft 104 and intermediate shaft 14 are properly aligned at the time of coupling. As the drive shaft 104 is permitted a measure axial movement during coupling the cylindrical spring 118 bearing against the clutch member 106 biases that shaft toward the hand-piece 10. The ring 114 is received in the cylindrical slot 116 formed in housing 102 and facilitates the joinder of that housing and rear housing 12.

Turning to FIG. 1, it is seen that the rearward end 120 of rear housing 12 has a wide central opening 122 therein. To couple the drive housing 102 and rear housing 12 that drive housing is simple press-fit into the opening 122. The ring 114 bears against the walls of opening 122 which maintains the drive housing 102 therein but in a very releasable manner (in fact this arrangement permits the drive housing to rotate within the opening).

The coupling between the drive shaft 104 and intermediate shaft 14 is effected by the claw member 124. That claw member includes the unitary arms 126, 128 which extend outwardly from shaft 14 toward drive shaft 104. Centrally located in the claw member 124, is the hole 130 which, upon coupling of the housings 12 and 102, receives the guide member 112. Upon coupling, the arms 126, 128 generally contact the base 110 but can be initially received within the notches 108. If initial contact is made with the base, with the drive shaft turning, the arms 126, 128 slide over the base 110 and into the notches 108 and continue sliding until they are centrally positioned therein. Coupling is then complete and the forward shaft 36 and hence the shank 50 is thereby rotated via the intermediate shaft 14 and the gear and pinion 18, 62 arrangement. Bearing arrangements 130 may be provided about the shaft 14 in the vicinity of the claw 124 the function of which is similar to that of the other bearings. At no time during connection or disconnection need the motor be shut-off or the drive shaft 104 slowed down or stopped. The convenience and time saving features of this arrangement are evident.

Turning now to FIG. 4, there is illustrated preferred structure for connecting the shank 50 to the forward shaft 36. In this embodiment the forward most part 140 of shaft 36 is split or has the slots 142 (only one of which is illustrated). The front or nose 144 of part 140 is beveled, the rear has an external thread 146 and there is a central bore 148 of a diameter slightly greater than that of the shank 50 for the reception of the same therein. A collect member 150 has an opening which is internally threaded 154 in the rear part and which tapers in the forward part. To fix a shank 50 withing shaft 36, the collect 150 is screwed onto the part 140. Concurrently, the internal wall 156 of the collet tapered section contacts the nose 144 and tends to squeeze the same. Continued turning of the collect reduces the width of slot 142 until the shank 50 is firmly grasped within bore 148. Reversing this procedure will effect removal of the collect 150 and release of the shank 50.

To facilitate the just described movements the flat surfaces 160, 162 are provided on the front of the collet 150. These surfaces are adapted to be grasped by an appropriate key or pliers to rotate the collect 150. It is for this purpose that nozzle 42 is threadedly engaged to housing 32. Its removal exposes the surfaces 160 and 162 for grasping by the key of pliers.

It has been seen that the present invention provides a novel surgical drill which is especially useful for surgical procedures which require drilling deep within the body. The present invention includes superior structural and operating characteristics than have heretofore been available in long, slender drills. It is evident that many changes may be made in the details of the instant invention without departing from the spirit and scope of the appended claims, which changes are intended to be embraced therewithin.

Claims

What is claimed is:

1. A surgical drill of the type comprising:

a. a hand-piece housing

b. a compound driven shaft rotatably mounted in said housing having aligned forward and intermediate shaft members, a pinion on said forward shaft member adjacent said intermediate shaft member, a drive gear mounted on said intermediate shaft and member the teeth of which extend outwardly therefrom toward said pinion, said gear and pinion mating in operative driving relation.

c. a cutting element having a shank releasably connectable to said driven shaft

d. means to exchangeably and operatively couple said cutting element and said driven shaft which comprises a slotted shaft front-piece having a central opening therein adapted to receive the shank of said cutting element, and a collet adapted to fit over said shank and said front-piece and threadedly engage with said front-piece so as to releasably hold said shank in said shank.

e. a drive housing including drive means therein having a drive shaft

f. means to detachably connect said hand-piece housing to said drive housing and

g. means to exchangeably and operatively couple said drive and driven shafts which comprises a clutch member attached to said drive shaft, a claw member on rear end of said intermediate shaft member of said compound driven shaft having cooperating arm members extending therefrom toward said clutch member adapted to mate in operative driving relation when said hand-piece is connected to said drive housing.