Rotary and oscillating surgical bone removal tool with tool exposure mechanism and locking collet

Abstract

A surgical device for cutting or shaving bone or tissue includes an outer housing having a collet secured to an inner circumferential surface thereof, the collet including one or more apertures defined therein. The housing includes an elongated tube extending therefrom that is configured to support a surgical tool at a distal end thereof. A gear assembly is disposed within the housing and configured to drive a surgical tool, the gear assembly including a drive gear housing selectively movable within the housing to switch the gear assembly between an oscillating mode and a rotating mode to drive the surgical tool. A motor is operably coupled to the gear assembly such that upon activation of the motor, the motor oscillates or rotates the surgical tool depending on a position of the drive gear housing within the housing.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Patent Application Nos. 63 / 425,872 and 63 / 425,870, filed on November 16, 2022, and U.S. Provisional Patent Application No. 63 / 442,222, filed on January 31, 2023. The entire contents of all of the above applications are incorporated herein by reference. Technical field

[0003] The present disclosure generally relates to devices and systems for cutting and treating bone and hard tissue. The devices and systems of the present disclosure may be particularly applicable to orthopedic applications and other surgical procedures that require bone removal. Background art

[0004] The devices and systems according to the present disclosure may be applicable to a variety of procedures, including orthopedic procedures, spinal procedures, cranial procedures, and other procedures that require bone or hard tissue removal. During a given procedure, a motor is used to power a drill disposed at the distal end of a surgical tool. Typically, the tool rotates at a very high RPM, which allows the dissecting tip of the drill of the tool to be inserted into bone or, in some cases, to cut or shave bone using one or more grooves on the dissecting tip of the drill. However, in some cases, a rotating drill bit, if not handled properly, may capture adjacent tissue, causing the adjacent tissue to wrap around the drill bit when the surgeon attempts to manipulate and clear delicate tissue, nerves, and ligaments and accidental contact with the drill tip.

[0005] One solution is to manufacture a surgical bone cutting / dissecting tool that uses a drill bit and a motor that employ an oscillating motion to cut bone and hard tissue. By oscillating the drill bit, if the drill bit contacts tissue, the tissue is less likely to be captured and wrapped around the drill bit. Summary of the invention

[0006] According to the present disclosure, there is provided a surgical device for cutting or shaving bone or tissue. The surgical device includes an outer housing having a chuck fixed to its inner circumferential surface. The chuck includes a series of openings defined around its circumference. The housing includes an elongate tube extending therefrom, and the elongate tube is configured to support a surgical tool at its distal end. A gear assembly is disposed within the housing and is configured to drive the surgical tool. The gear assembly includes a drive gear housing that is selectively movable within the housing to switch the gear assembly between an oscillating mode and a rotating mode, thereby driving the surgical tool. A motor is operably coupled to the gear assembly such that, upon startup of the motor, the motor causes the surgical tool to oscillate or rotate depending on the position of the drive gear housing within the housing.

[0007] In aspects in accordance with the present disclosure, the housing includes a slot defined in its proximal end that communicates with a post extending from the drive gear housing such that as the housing moves, the slot correspondingly moves the post within the slot. In other aspects in accordance with the present disclosure, the slot is arcuate and the post moves within the slot as the housing rotates relative to the chuck. In yet other aspects in accordance with the present disclosure, the surgical device further includes a lever lock operatively coupled to the housing and wherein, upon actuation, the lever lock allows the user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of a series of openings defined within the chuck.

[0008] In aspects in accordance with the present disclosure, when set in an oscillating mode, the gear assembly operatively engages a linkage that oscillates the swing gear by a rotational angle β that depends on the distance between the axis of the motor and the axis of the swing gear. In other aspects in accordance with the present disclosure, the distance between the axis of the motor and the axis of the swing gear changes as the housing rotates relative to the chuck, thereby changing the rotational angle β.

[0009] In aspects in accordance with the present disclosure, a lever lock is operatively coupled to the housing and wherein, upon actuation, the lever lock allows the user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of a series of openings defined within the chuck and wherein each of the series of openings sets the rotational angle β of the swing gear. In other aspects in accordance with the present disclosure, one or more of the series of openings defines the rotational angle β of the swing gear as being approximately 59°, approximately 68°, or approximately 76°.

[0010] A surgical device for cutting or shaving bone or tissue is provided in accordance with the present disclosure, the surgical device including an outer housing having a chuck fixed to its inner circumferential surface, the chuck including a series of openings defined about its circumference. The housing includes an elongate tube extending therefrom that is configured to support a surgical tool at its distal end. A gear assembly is disposed within the housing and is configured to drive the surgical tool, the gear assembly including a drive gear housing that is selectively movable within the housing to switch the gear assembly between an oscillating mode and a rotational mode to drive the surgical tool. A motor is operatively coupled to the gear assembly such that upon startup of the motor, the motor oscillates or rotates the surgical tool depending on the position of the drive gear housing within the housing, wherein when set in a rotational mode, the gear assembly operatively engages a direct drive gear that is coupled to an idler gear that drives the surgical tool.

[0011] In aspects in accordance with the present disclosure, the housing includes a slot defined in its proximal end that is in communication with a post extending from the drive gear housing such that as the housing moves, the slot correspondingly causes the post to move within the slot. In other aspects in accordance with the present disclosure, the slot is arcuate and the post moves within the slot as the housing rotates relative to the chuck.

[0012] In aspects in accordance with the present disclosure, a lever lock is operatively coupled to the housing and wherein, upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of a series of openings defined in the chuck. In other aspects in accordance with the present disclosure, upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of a series of openings defined in the chuck and wherein the drive gear housing is moved by rotating the housing to one of the series of openings to configure the surgical device into a rotational mode. In still other aspects in accordance with the present disclosure, as the housing rotates relative to the chuck, the post moves along the slot to disengage from a series of gears associated with an oscillatory mode and engage a series of gears associated with a rotational mode. In yet other aspects in accordance with the present disclosure, the drive gear housing includes a pin slot defined therein that is configured to at least partially house an idler gear therein and that is configured to limit movement of the drive gear housing in a linear direction as the housing rotates.

[0013] A surgical device for cutting or shaving bone or tissue is provided in accordance with the present disclosure, the surgical device including an outer housing having a chuck fixed to its inner circumferential surface, the chuck including a series of openings defined about its circumference. The housing includes an elongate tube extending therefrom that is configured to support a surgical tool at its distal end. A gear assembly is disposed within the housing and is configured to drive the surgical tool, the gear assembly including a drive gear housing that is selectively movable within the housing to switch the gear assembly between an oscillatory mode and a rotational mode to drive the surgical tool. A motor is operatively coupled to the gear assembly such that upon startup of the motor, the motor causes the surgical tool to oscillate or rotate depending on the position of the drive gear housing within the housing, wherein when set to the rotational mode, the gear assembly operatively engages a direct drive gear that is coupled to an idler gear that drives the surgical tool, and wherein when set to the oscillatory mode, the gear assembly operatively engages a linkage that causes a wobble gear to oscillate at a rotational angle β that depends on the distance between the axis of the motor and the axis of the wobble gear.

[0014] In aspects in accordance with the present disclosure, the housing includes a slot defined in its proximal end that communicates with a post extending from the drive housing such that as the housing moves, the slot correspondingly moves the post within the slot. In other aspects in accordance with the present disclosure, the slot is arcuate and the post moves within the slot as the housing rotates relative to the chuck. In aspects in accordance with the present disclosure, a lever lock is operatively coupled to the housing and wherein, upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of a series of openings defined within the chuck.

[0015] In aspects in accordance with the present disclosure, the surgical tool includes a drill bit configured to cut or shave tissue when set in an oscillatory mode or a rotational mode.

[0016] A surgical device for cutting or shaving bone or tissue is provided in accordance with the present disclosure, the surgical device including a housing that includes an elongate tube extending therefrom, the elongate tube configured to receive an axis of a surgical tool therein. A gear assembly is disposed within the housing and includes a drive shaft configured to drive the surgical tool. A locking collar is disposed at a distal end of the housing and includes a helical groove defined therein, the helical groove configured to at least partially receive a portion of a ball bearing. A chuck is disposed within the locking collar and includes a pit defined therein for holding a relative portion of the ball bearing, the chuck being movable within the locking collar between a proximal position and a distal position.

[0017] A locking bearing is disposed within the chuck and is configured to receive a distal end of the drive shaft of the gear assembly, the distal end of the drive shaft being configured to operatively receive a proximal end of the axis of the surgical tool upon initial insertion when the chuck is disposed in the proximal position. After inserting the proximal end of the axis of the surgical tool into the distal end of the drive shaft, the locking collar is rotated in a first direction to move the ball bearing along the helical groove, which in turn correspondingly moves the ball bearing and the pit to translate the chuck to the distal position and force the locking bearing onto the distal end of the drive shaft, thereby firmly engaging the distal end of the drive shaft to the proximal end of the surgical tool.

[0018] In aspects in accordance with the present disclosure, the proximal end of the surgical tool and the distal end of the drive shaft include mating mechanical interface elements to effect their initial engagement.

[0019] In aspects in accordance with the present disclosure, the distal end of the drive shaft includes a plurality of fork-like teeth that mate in a spring-like manner to facilitate engagement with the proximal end of the tool shaft upon insertion of the tool shaft. In other aspects in accordance with the present disclosure, as the locking collar is rotated in the first direction, the locking bearing presses the plurality of fork-like teeth against the proximal end of the tool shaft to secure the tool shaft thereto.

[0020] In aspects in accordance with the present disclosure, when the locking collar rotates in a second direction opposite the first direction, the ball bearing moves along the helical groove, which in turn correspondingly moves the ball bearing and the pit to translate the chuck to a proximal position and forces the locking bearing to move proximally along the drive shaft to release the proximal end of the surgical tool.

[0021] In aspects in accordance with the present disclosure, the distal end of the drive shaft includes a plurality of fork-like teeth that are spring-like configured to facilitate engagement with the proximal end of the tool shaft when inserting the tool shaft, and wherein when the locking collar rotates in the second direction and the chuck translates proximally, the plurality of fork-like teeth facilitate release of the tool shaft from the drive shaft.

[0022] In aspects in accordance with the present disclosure, the drive shaft is configured to releasably secure the tool shaft within the housing using mechanically mating components including snap-fit components, keyed components, press-fit components, tongue-and-groove components, threaded mating components, and ball-and-socket components.

[0023] A surgical device for cutting or shaving bone or tissue is provided in accordance with the present disclosure, the surgical device including a housing having an elongate tube extending therefrom, the elongate tube configured to receive the shaft of a surgical tool therein such that the length of the distal end of the surgical tool remains exposed, the elongate tube including a pit defined therein configured to secure a portion of a ball bearing therein. A tool exposure mechanism is disposed about the elongate tube and rotatably attached to the distal end of the housing, the tool exposure mechanism including a helical groove defined therein and extending therealong configured to receive an opposite end of the ball bearing. The tool exposure mechanism is capable of rotating in a first direction to move the ball bearing along the helical groove, which in turn correspondingly moves the ball bearing and the pit to translate the elongate tube relative to the shaft of the surgical tool and control the amount of exposure of the distal end of the surgical tool in the first direction.

[0024] In aspects in accordance with the present disclosure, rotation of the tool exposure mechanism in an opposite direction controls the amount of exposure of the distal end of the surgical tool in the opposite direction.

[0025] In aspects in accordance with the present disclosure, the pit is defined in the proximal end of the elongate tube.

[0026] In aspects in accordance with the present disclosure, the surgical device further includes a gear assembly disposed within the housing, the gear assembly having a drive shaft configured to drive the surgical device,

[0027] The gear assembly is capable of selectively moving between an oscillatory mode and a rotational mode to drive the surgical tool.

[0028] In aspects in accordance with the present disclosure, the surgical device further includes an electric motor operatively coupled to a gear assembly such that upon activation of the electric motor, the electric motor performs at least one of oscillating or rotating a surgical tool depending on the position of the gear assembly.

[0029] Provided in accordance with the present disclosure is a surgical device for cutting or shaving bone or tissue, the surgical device including a housing configured to support a shaft of a surgical tool and a motor input. A gear assembly is disposed within the housing and is configured to drive the surgical tool. The gear assembly is operatively engaged with a support chassis disposed within the housing. The support chassis is selectively movable relative to the housing to switch the gear assembly between an oscillating mode and a rotating mode, in the oscillating mode, a drive gear of the gear assembly engages a swing gear and a link of the gear assembly that engages the motor input, and in the rotating mode, the drive gear of the gear assembly engages a direct drive gear of the gear assembly that engages the motor input.

[0030] In aspects in accordance with the present disclosure, the support chassis is supported on a spring. In other aspects in accordance with the present disclosure, the surgical device includes a guide plate disposed within the housing and configured to guide movement of the support chassis between modes. In still other aspects in accordance with the present disclosure, an outer ring is disposed around the housing and is configured to operatively engage the guide plate, the outer ring being movable to lock the guide plate relative to the housing in a selected operating mode. In yet other aspects in accordance with the present disclosure, the outer ring may be rotated or longitudinally displaced to lock the guide plate relative to the housing.

[0031] In aspects in accordance with the present disclosure, the drive gear is configured to disengage from a gear from a previous mode before engaging a gear of the next mode.

[0032] In aspects in accordance with the present disclosure, one or more of the gears of the gear assembly include chamfered gear teeth to facilitate engagement with other gears of the gear assembly during a transition between modes. In other aspects in accordance with the present disclosure, the angle of the chamfer on the gear teeth is in the range of about 5 degrees to about 35 degrees.

[0033] Provided in accordance with the present disclosure is a surgical device for cutting or shaving bone or tissue, the surgical device including a housing configured to support a shaft of a surgical tool and a motor input. A gear assembly is disposed within the housing and is configured to drive the surgical tool. The gear assembly is operatively engaged with a support chassis disposed within the housing. The support chassis is configured to support a pair of synchronizing gears that toggle on top of a spring to switch the gear assembly between an oscillating mode and a rotating mode, in the oscillating mode, a drive gear of the gear assembly engages a swing gear and a link of the gear assembly that engages the motor input, and in the rotating mode, the drive gear of the gear assembly engages a direct drive gear of the gear assembly that engages the motor input.

[0034] In aspects in accordance with the present disclosure, the synchronizing gears include proximally facing blocking rings that are configured to engage corresponding distally facing blocking rings disposed on the direct drive gear and the oscillating gear when moved into engagement with the corresponding distally facing blocking rings during respective engagement modes.

[0035] In aspects in accordance with the present disclosure, the surgical device includes a guide plate disposed within the housing and configured to guide movement of the support chassis between modes. In further aspects in accordance with the present disclosure, an outer ring is disposed about the housing and configured to operatively engage the guide plate, the outer ring being movable to lock the guide plate relative to the housing in a selected operating mode. In still further aspects in accordance with the present disclosure, the outer ring may be rotated or longitudinally displaced to lock the guide plate relative to the housing.

[0036] In aspects in accordance with the present disclosure, the drive gear is configured to disengage from the gear from the previous mode before engaging the gear of the next mode.

[0037] In aspects in accordance with the present disclosure, one or more of the gears of the gear assembly include chamfered gear teeth to facilitate engagement with other gears of the gear assembly during transitions between modes. In other aspects in accordance with the present disclosure, the angle of the chamfer on the gear teeth is in the range of from about 5 degrees to about 35 degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In the drawings, the same numbers indicate the same components in several views:

[0039] Figure 1 is a top view of a cutting and shaving surgical device according to an embodiment of the present disclosure;

[0040] Figure 2 is taken along Figure 1 centerline A-A of Figure 1 a side cross-sectional view of the cutting and shaving surgical device,

[0041] showing the gear assembly disposed therein;

[0042] Figure 3 is a Figure 1 side view of the cutting and shaving surgical device;

[0043] Figure 4A is a Figure 1 rear perspective view of the gear assembly and motor of the cutting and shaving surgical device;

[0044] Figures 4B to 4C is a schematic view of a four-bar linkage diagram showing the angular displacement of the oscillating gear for two different gear configurations;

[0045] Figure 4D is a front perspective view of a gear housing that is movable and lockable relative to an electric motor via an angular displacement locking mechanism;

[0046] Figures 5A to 5C are various enlarged views of a surgical tool for use with an embodiment of the cutting and shaving surgical device described herein;

[0047] Figure 6A is an internal cross-sectional view of a cutting and shaving surgical device according to another embodiment of the present disclosure, the cutting and shaving surgical device being capable of rotating and oscillating a surgical tool using a single drive gear;

[0048] Figure 6B is Figure 6A and Figures 7A to 14 a rear perspective view of an internal gear arrangement of a surgical device and an electric motor set in an oscillating mode;

[0049] Figures 6C to 6D is Figure 6A and Figure 6B a side cross-sectional view of a surgical device, illustrating an alternative embodiment of a tool exposure mechanism in various exposed positions;

[0050] Figures 6E to 6F is Figure 6A and Figure 6B a side cross-sectional view of a surgical device, illustrating an alternative embodiment of a locking collar in various engaged positions;

[0051] Figure 7A is Figure 6A an internal cross-sectional view of a cutting and shaving surgical device, wherein an internal gear assembly is set in a first configuration to produce a first oscillation angle of a surgical tool;

[0052] Figure 7B is a rear perspective view of a chuck configured to lock a gear assembly relative to the chuck at one or more angular positions when the gear assembly is rotated relative to the chuck by a lever lock;

[0053] Figure 8A is Figure 6A an internal cross-sectional view of a cutting and shaving surgical device, wherein the gear assembly is set in a second configuration to produce a second oscillation angle of a surgical tool;

[0054] Figure 8B is a schematic diagram of a four-bar linkage showing the angular displacement of a swing gear for a gear assembly in a second configuration;

[0055] Figure 9 is Figure 6AInternal cross-sectional view of a cutting and shaving surgical device, where the gear assembly is set in a third configuration, thereby producing the third maximum oscillation angle of the surgical tool;

[0056] Figure 10 is Figure 6A Internal cross-sectional view of a cutting and shaving surgical device, where the drive gear housing moves the drive gear assembly into a rotational mode while disengaging the oscillation mode;

[0057] Figure 11 Perspective view of a gear housing for a drive assembly that cooperates with the drive gear housing to move the surgical device between a rotational mode and an oscillation mode as it rotates;

[0058] Figure 12 is Figure 10 Perspective view of the drive gear housing of

[0059] Figure 13 is shown in a rotational mode Figures 6A to 12 Rear perspective view of the surgical device of

[0060] Figure 14 is Figures 6A to 13 Rear perspective view of the internal gear arrangement of the surgical device of when set in a rotational mode;

[0061] Figures 15A to 15B Schematic representation of an alternative embodiment of a gear assembly for use with a shaving surgical device, where the gear housing cooperates with the drive gear housing to move the surgical device between a rotational mode and an oscillation mode through the movement of a common drive gear;

[0062] Figures 16A to 16B is Figures 15A to 15B Schematic representation of the shown embodiment, showing the engagement of various gears and the corresponding gear movements during two different operating modes;

[0063] Figure 17 Enlarged perspective view of one of the gears, showing the chamfered profile of the corresponding gear teeth to facilitate meshing between the gears, especially in cases of slight misalignment when switching between operating modes;

[0064] Figures 18A to 18B Schematic representation of another alternative embodiment of a gear assembly for use with a shaving surgical device, where the gear housing cooperates with the drive gear housing to move the surgical device between a rotational mode and an oscillation mode through engagement with a toggle gear;

[0065] Figures 19A to 19B is Figures 18A to 18BSchematic representation of an embodiment shown, showing the engagement of various gears and the corresponding gear movements during two different operating modes;

[0066] Figures 20A to 20F is a schematic representation of an alternative oscillating mechanism for use with a shaving surgical device including alternating oscillating blades;

[0067] Figure 21 is a schematic view of another alternative oscillating mechanism for use with a shaving surgical device including alternating friction discs;

[0068] Figure 22 is a schematic view of another alternative oscillating mechanism for use with a shaving surgical device including alternating compound gears;

[0069] Figure 23 is a schematic representation of another alternative oscillating mechanism for use with a shaving surgical device, the oscillating mechanism including a gear oscillation increasing mechanism that can increase the oscillation angle of the oscillation shaft; and

[0070] Figure 24 is a schematic representation of another alternative oscillating mechanism for use with a shaving surgical device, the oscillating mechanism including a mechanism that converts reciprocating motion into an oscillating output to control the shaft. Detailed Description

[0071] Figures 1 to 3 Illustrates one embodiment of a surgical device 10 that is configured for use in orthopedic and cranial surgical procedures for dissecting, cutting, shaving, and otherwise removing bone and hard tissue. The device 10 includes a housing 20 that is configured to be manipulated by a surgeon and has a motor 50 operably associated therewith. The motor 50 may ultimately be connected to a power source (not shown) or be configured to accommodate a battery (not shown) for portable use. The motor 50 is configured to operate at various speeds, which may be controlled by the user via a speed dial or switch on the housing 20 or may be controlled at the power source. A slender tube 12 extends from the distal end of the housing 20 and is configured to support a surgical tool 100, such as a drill bit, dissection head, or bone scraper, at its distal end 16. The proximal end 14 of the tube 12 is removably engageable with the housing 20 and can be locked therein via a locking chuck 70, the description of which is provided below. The slender tube 12 may be configured to support the surgical tool 100 on top of bearings (not shown) spaced along it.

[0072] The housing 20 includes a chamber 21 defined therein that is configured to accommodate a gear assembly 40 operably engaged with the motor 50. More specifically, the gear assembly 40 includes an input shaft 41 that is configured to operably engage the motor 50 (Figure 2 ) of the motor rotor shaft or chuck (not shown) such that the rotational output of the rotor shaft rotates the input shaft 41 at a 1:1 ratio accordingly. In an embodiment, other gear ratios are contemplated. The input shaft 41 is connected to a series of gears disposed within the housing 20, and these gears cooperate to rotate the gear output shaft 42 at a desired speed (revolutions per minute or RPM). Additionally, in some overall systems, the rotor shaft of the motor 50 can be shared and can be the input gear 41 of the gear assembly 40.

[0073] The gear output shaft 42 is coupled to a connecting rod 44 that drives a wobble gear 48 such that the rotational output of the output shaft 42 is converted into an oscillatory motion of the wobble gear 48. The wobble gear 48 is in turn coupled to an oscillation converter 46 (which can include any known type of oscillation converter mechanism), and this oscillation converter is ultimately connected at its proximal end to the tool shaft 25 of the surgical tool. Generally, the oscillation converter 46 is a subassembly of components that converts the rotational motion of the output gear 42 into an oscillatory motion to move the tool shaft 25. In this case, the subassembly of components includes the output gear 42, the connecting rod 44, the wobble gear 48, and the tool drive shaft 37.

[0074] The gear assembly 40 is configured to be selectively engageable with one or more oscillation components 46, and the one or more oscillation components can be selectively adjusted to change the oscillation angle of the wobble gear 48, as explained in more detail below with respect to Figure 4D More specifically, the housing 20 includes an angular displacement mechanism or lock 80 that is configured to selectively lock the motor 50 in one of a series of angular positions indicated by markings 82a to 82c disposed thereon. Actuation of the lock 80 (e.g., pressing the lock 80 into the housing 20 in the direction "P") causes the lock 80 to rotate about a pivot 81, enabling the user to rotate the orientation of the motor 50 relative to the housing 20 and the gear assembly 40. As explained in more detail with respect to Figures 4A to 4D Rotation of the motor 50 in the direction "A" reorients the input shaft 41 and the shaft 42 relative to the gear assembly 40, such that the gear assembly 40 correspondingly rotates the oscillation angle of the wobble gear 48, which in turn corresponds to the oscillation angle of the surgical tool 100 (e.g., a drill).

[0075] In an embodiment, the oscillation angle of the wobble gear can be a 1:1 ratio or a greater ratio relative to the oscillation angle, depending on the specific purpose. In an embodiment, the ratio can be approximately 1:2. In other embodiments, the ratio can be approximately 1:3.5.

[0076] As described above, the proximal end 25a of the tool shaft 25 is configured to selectively engage a chuck 35 disposed within the housing 20 and operatively associated with a locking collar 70. The locking collar 70 is rotatable between an open position that orients the chuck 35 to selectively receive the proximal end 25a of the tool shaft 25 and a locking position that engages the chuck 35 to the proximal end 25a of the tool shaft 25. In an embodiment, the proximal end 25a of the tool shaft 25 is keyed to facilitate engagement with the chuck 35. The user simply rotates the locking collar 70 in the opposite direction of arrow "L" to load the tool shaft 25 and the surgical tool thereon, and then rotates the locking collar 70 in the opposite direction "L" to lockingly engage the tool shaft 25 within the chuck 35. Figure 6E and Figure 6F Details of an alternative locking collar 370 are discussed. The chuck 35 includes a drive shaft 37 disposed on its proximal end, which is configured to engage a wobble gear 48 such that oscillation of the wobble gear 48 causes corresponding oscillation of the drive shaft 37, which in turn causes oscillation of the tool shaft 25 upon engagement.

[0077] Turning to Figures 4A to 4D , Figure 4A a rear perspective view of the input shaft 41 connected to the gear assembly 40 and the output shaft 42 is shown, as well as how the link 44 causes oscillation of the wobble gear 48, which in turn causes oscillation of the tool shaft 25. Figure 4B is a schematic representation of the mechanical structure behind the four-bar linkage assembly of the wobble gear 48 and the relationship between the angular stroke of the wobble gear 48 and the stroke or angular displacement of the wobble gear 48, as it relates to the position of the gear assembly housing 20. More specifically, and as described above, the gear assembly housing 20 includes an angular displacement lock 80 that is configured to selectively lock the motor 50 in one of a series of angular positions represented by marks 82a to 82c disposed thereon.

[0078] The oscillation of the wobble gear 48 is based on the following factors as shown in Figure 4B : the distance "H" between the wobble gear axis SGA and the output shaft axis OSA; "L" - the length of the link 44; "r1" - the distance from the center where the link 44 is connected to the output shaft axis OSA; "r2" - the distance from the center where the link 44 is connected to the wobble gear axis SGA.

[0079] Actuation of the lock 80 (e.g., pressing the lock 80 into the housing 20 in the direction "P") causes the lock 80 to rotate about the pivot 81, enabling the user to rotate the orientation of the motor 50 relative to the gear assembly housing 20 and the gear assembly 40. As shown in Figure 4B , this causes the center of the output shaft axis OSA to move a distance "H", thereby achieving an angular displacement of the wobble gear 48, as shown.

[0080] By way of comparison, for example, Figure 4B shows the gear housing 20 with the lock 80 in position 82c, in which the oscillating gear 48 is at a minimum angular displacement (59°), and the motor output shaft axis OSA is substantially aligned with the oscillating gear axis SGA. Further, the distance “H” is at a maximum. When the user rotates the motor 50 to increase the angular displacement, for example to position 82b, the angular displacement of the motor output shaft axis OSA moves away from the oscillating gear axis SGA, and the angle α increases (see Figure 4C ), while the distance from the oscillating gear axis SGA to the output gear axis “H” decreases (see Figure 4C ). As a result, the total angular travel β of the oscillating gear increases (68°). At position 82a, the motor 50 is rotated to the maximum angular displacement orientation, and the oscillating gear 48 oscillates at the maximum angle. As described herein, this allows the surgical tool 100 to cut more invasively, as explained in more detail below.

[0081] The housing 20 also supports a tool exposure mechanism 30 that is configured to adjust the exposure length of the surgical tool 100 relative to the distal end 16 of the elongate tube 12. This provides additional flexibility to the surgeon when using the surgical device 10. More specifically, as Figure 2 best shown in, the chuck 35 is capable of selectively moving within a chamber 39 defined in the housing 20. Rotation of the tool exposure mechanism 30 in the counterclockwise direction “R1” causes the chuck 35 to move a corresponding distance “E1” within the chamber 39. Movement of the chuck 35 in the direction “E1” in turn causes the surgical tool 100 to be exposed a corresponding distance “E2” from the distal end 16 of the elongate barrel 12. In an embodiment, “E1” and “E2” may be equivalent, or in other embodiments, “E1” and “E2” may be different and may move according to a specific gear ratio. Rotation of the tool exposure mechanism 30 in the opposite direction will cause the surgical tool 100 to retract into the distal end 16. In an embodiment, other types of actuators are contemplated, such as a sliding actuator, a toggle switch, etc. Discussed below in Figure 6C and Figure 6D discusses an alternative embodiment of the tool exposure mechanism 330 in which internal components of the elongate tube are configured to slide relative to the drive shaft to adjust tool exposure.

[0082] In use, the surgeon first loads the drive shaft 25 of the surgical tool 100 into the housing 20 of the device 10 by rotating the lock 70 in the counterclockwise direction (opposite to “L”) to open the chuck 35. Once opened, the surgeon slides the shaft 25 within the elongate tube 12 such that the proximal end 25a of the shaft 25 bottoms out into the chuck 35 or otherwise engages the chuck 35.

[0083] The surgeon then rotates the lock 70 in the reverse “L” direction to close the chuck 35 onto the proximal end 25a and lock the tool shaft 25 within the device 10. Once locked, the device 10 is ready for use.

[0084] If the surgeon desires to change the angular displacement of the oscillation of the surgical tool 100 for a particular surgical purpose, e.g., to adjust the invasiveness (more delicate cutting or more invasive cutting) of the surgical tool 100, the surgeon simply presses the angular displacement lock 80 and rotates the motor 50 relative to the housing 20. As described above, rotation of the motor 50 correspondingly adjusts one or more gears of the gear assembly 40, which in turn adjusts the swing angle of the oscillating gear 48, thereby effecting the oscillation angle of the surgical tool 100.

[0085] Additionally, if the surgeon desires to change the exposed length “E2” of the surgical tool 100 for a particular surgical purpose, e.g., better control, visibility, or insertion depth, the surgeon simply rotates the tool exposure mechanism 30 to move the chuck 35, which in turn extends or retracts the exposed length “E2” of the surgical tool 100 relative to the distal end 16 of the elongate tube 12.

[0086] Turning to Figures 5A to 5C , which shows various views of the surgical tool 100, in this particular case, the surgical tool is shown as a drill bit that can be used to cut into bone or hard tissue and shave. More specifically, the surgical tool 100 (hereinafter referred to as “drill bit 100”) is provided at the distal end 25b of the drive shaft 25 and includes a series of cutting grooves (generally identified as grooves 110 and 120) disposed therearound, and a cutting tip 130 at its most distal end. Generally speaking, the cutting tip 130 facilitates cutting into bone or hard tissue, while the grooves 110 and 120 facilitate shaving. However, the grooves 110 and 120, as well as the cutting tip 130, may each be configured to facilitate both cutting and shaving depending on the particular purpose.

[0087] The drill bit 100 includes two pairs of opposing grooves, namely grooves 110a, 110b and grooves 120a, 120b. Any number of cutting grooves may be employed, but for the purposes of this text, the grooves are described as a pair of grooves 110a, 110b. Grooves 110a, 110b are generally larger than grooves 120a, 120b and converge to form a cutting tip 130 at their distal ends. Groove 110a includes a deep recess 115a defined between opposing cutting edges 112a, 112b that facilitates removal of bone fragments when the drill bit 100 oscillates. Groove 110b includes a similar element located on the opposite side of the drill bit 100, namely, a recess 115b defined between cutting edges 114a, 114b. Grooves 110a, 110b and cutting tip 130 cooperate to facilitate cutting into bone or hard tissue. The cutting edges 112a, 112b and 114a, 114b of grooves 110a, 110b are simultaneously configured to cooperate with grooves 120a, 120b to facilitate shaving or side cutting.

[0088] Groove 120a includes a deep recess 125a defined between opposing cutting edges 122a, 122b that facilitates removal of bone fragments during shaving when the drill bit 100 oscillates. Groove 120b includes a similar element located on the opposite side of the drill bit 100, namely, a recess 125b defined between cutting edges 124a, 124b. Sections 135a to 135d are defined between adjacent grooves, for example, section 135a is defined between groove 110a and groove 120a and is configured to similarly facilitate removal. Sections 135a to 135d are also configured to facilitate removal of bone or tissue during both plunge cutting and shaving.

[0089] Compared to rotary cutting where a single leading cutting edge is typically required to cut bone when a rotary cutting tool rotates in a single direction, the drill bit 100 of the present disclosure includes two edges located on opposite sides of recess 115a that provide a leading cutting edge (e.g., cutting edge 112b) during clockwise rotation and a leading cutting edge (e.g., cutting edge 112a) during counterclockwise rotation. This enhances plunge cutting using the larger grooves 110, 110b. Similarly, grooves 120a, 120b each include opposing cutting edges, such as edges 114a, 114b, that act as leading edges for shaving bone and tissue.

[0090] By adjusting the oscillation angle by adjusting the lock 80 via the actuation angle and rotating the motor 50, the surgeon can select a larger oscillation angle Δ for more invasive cutting or a lower oscillation angle Δ for more delicate cutting. In an embodiment, the drill bit 100 can be keyed (or configured to allow insertion only in one direction). Without changing the speed of the motor 50, changing the oscillation angle Δ of the drill bit 100 will change the cutting performance of the drill bit 100. For example, if the oscillation angle Δ increases, the drill bit 100 will rotate more quickly and further increase the number of grooves cut into the bone. Similarly, if the oscillation angle Δ decreases, the drill bit 100 will rotate more slowly and travel a smaller radial distance, which reduces the number of grooves cut into the bone.

[0091] Figures 6A to 14 Another embodiment of a surgical device 300 is illustrated, which is configured for use in orthopedic and cranio-surgical procedures for dissecting, cutting, shaving, and otherwise removing bone and hard tissue. The surgical device 300 and the surgical device 10 are generally similar in some respects, except that the surgical device 300 has an additional capability of a rotational mode of the drill bit 100 when the drive gear housing 390 is moved to the rotational mode position,

[0092] as explained in more detail below. For the sake of brevity, some aspects of the surgical device 300 are not explained in detail and it should be understood that these aspects are similar to those of the surgical device 10.

[0093] Turning first to Figures 6A to 6B , which shows the surgical device 300, which includes an outer housing 360 that is configured to be mounted on a surgical robot and / or controlled by a surgeon, who has a motor 350 operatively associated therewith. The motor 350 can ultimately be connected to a power source (not shown) or be configured to house a battery (not shown) for portable use. The motor 350 is configured to operate at various speeds, which can be controlled by the user via a speed dial or switch on the housing 320 or can be controlled at the power source. An elongate tube 312 extends from the distal end of the housing 320 and is configured to support a surgical tool, such as the drill bit 100, a dissecting head, or a bone scraper, at its distal end 16, as described in detail above with reference to Figures 1 to 5C . The proximal end 314 of the tube 312 is removably engageable with the housing 320 and, when the drill bit 100 is locked via the locking chuck 370, the proximal end of the tube is likewise lockable in the housing in a manner similar to that described above.

[0094] The housing 320 is configured to accommodate a gear assembly 340 that operably engages a motor 350. More specifically, the gear assembly 340 includes an input shaft 341 that is configured to operably engage a rotor shaft or chuck (not shown) of the motor 350 such that the rotational output of the output gear rotates the input shaft 341 at a corresponding 1:1 ratio. Additionally, in some overall systems, the output gear of the motor 350 is commonly referred to as the input gear 341 of the gear assembly 340. In embodiments, other gear ratios are contemplated. The input shaft 341 is connected to a series of gears 340a - 340c disposed within the housing 320 that cooperate to rotate a gear output shaft 342 at a desired speed (revolutions per minute or RPM).

[0095] The gear output shaft 342 includes a distal end 342a coupled to a link 344 that drives a wobble gear 348 such that the rotational output of the output shaft 342 is converted into an oscillatory motion of the wobble gear 348. In other words, the rotational motion of the distal end 342a of the output shaft 342 causes the link 344 to move in a generally vertical arc (e.g., see Figure 4B and Figure 4C ), which in turn oscillates the wobble gear 348 and ultimately oscillates the tool shaft 325. As explained in more detail below, both the wobble gear 348 for the oscillatory mode, the direct drive gear 387 for the rotational mode, and the idler gear 339 ( Figure 14 ) are housed within a selectively movable drive gear housing 390. When set to the oscillatory mode, the wobble gear 348 meshingly engages a proximal end gear or drive shaft 337, and when set to the rotational mode, the idler gear 339 meshingly engages the proximal end gear of the drive shaft 337.

[0096] The gear assembly 340 is configured to be selectively cooperable with one or more oscillatory components that can be selectively adjusted to vary the oscillation angle of the wobble gear 348, as explained in more detail below. More specifically, the housing 320 includes a chuck housing 365 fixed to its inner circumferential surface that defines a series of circumferentially spaced openings 382a - 382c ( Figure 7B ). Similar to the device 10, an angular displacement or lever lock 380 enables a user to rotate the housing 320 relative to the motor 350 (or vice versa) and lock the housing 20 in various angular positions within the openings 382a - 382c relative to the motor 350.

[0097] Actuation of the lever lock 380 (e.g., overcoming the biasing of a spring 387 about a pivot 381 ( Figure 9)Press or push the lock 380 towards the housing 320) to rotate the lever lock 380, thereby enabling the user to freely rotate the orientation of the housing 320 and the gear assembly 340 relative to the motor 350. As described above with respect to Figures 4A to 4D and also specifically with respect to Figure 8B As explained, the distance between the axis SGA of the oscillating gear 348 and the axis OSA of the input gear 341 (in other words, Figure 8B the distance H in

[0098] Now turning to the various angular displacement configurations as shown in Figures 7A to 9 As shown, the lever lock 380 can be pushed down in the direction "P" around the pivot 381 ( Figure 9 ) to allow the housing 320 to move relative to the motor 350 in the direction of arrow "A", which in turn reorients the distance between the axis of the motor 350 and the axis of the oscillating gear 348, thereby increasing the oscillation angle β of the link 344. Figure 7A and Figure 7B show the surgical device 300 in the oscillating mode, where the lever lock 380 is in the first angular displacement position. Once the lever 380 is correctly aligned within the selected opening (e.g., opening 382c), the lever lock 380 is released and, under the biasing of the spring 387 ( Figure 9 ), the lever lock 380 returns to engage the opening 382c, which locks the housing 320 relative to the motor 350 in the first angular displacement position. When the motor 350 is started, and as explained in detail above, the gear assembly 340 and the link 344 cooperate to oscillate the oscillating gear 348 at a specific oscillating rotation angle β, which in turn causes the drill bit 100 to oscillate at a corresponding oscillating rotation angle Δ. In this particular case, at the first angular displacement position, the oscillating rotation angle β of the oscillating gear can range from approximately 48° to approximately 64°.

[0099] It is important to note that during the start-up of the motor 350, the axis of rotation OSA of the input gear 341 is parallel but not coincident with the axis SGA of the rotating oscillating gear 348. As described above, the two axes are offset from each other by a distance "H", and as the distance "H" changes, the oscillation angle β changes (e.g., see Figure 4A , Figure 4B and Figure 8B ).

[0100] If it is desired to use the drill bit 100 to shave bone or tissue in a more invasive manner, the surgeon can choose to further increase the oscillation angle β by rotating the housing 320 to the second angular displacement position as shown in Figure 8A and Figure 8B . In the same manner as described above with respect to Figure 7A and Figure 7BIn a similar manner, the lever lock 780 is depressed about the pivot 381 ( Figure 9 ) against the bias of the spring 387 to allow the surgeon to rotate and reorient the housing 320 to a second angular displacement position and then release the lever lock 380 to lock within the opening 382b. When the motor 350 is activated, the gear assembly 340 and the linkage 344 cooperate to oscillate the oscillating gear 348 through a specific oscillating rotation angle β, which in turn causes the drill bit 100 to oscillate through a corresponding oscillating rotation angle Δ. In this particular case, at the second angular displacement position, the oscillating rotation angle β of the oscillating gear can range from about 65° to about 72°.

[0101] As described above and as shown in the comparison of Figure 4A and Figure 4B (which is similar to Figure 8B , but for the surgical device 300), as the lever lock 380 moves from the first angular displacement position to the second angular displacement position, the distance "H" between the axis OSA and the axis SGA changes (decreases), resulting in a change (increase) in the swing angle β of the oscillating gear 348.

[0102] If the surgeon wishes to maximize the cutting effectiveness of the drill bit 100 for shaving purposes and use the drill bit 100 in the most invasive design manner to shave bone or tissue, or perhaps insert the drill bit 100 into bone or tissue, the surgeon can choose to further increase the oscillation angle β by rotating the housing 320 to the final angular displacement position intended for the oscillation of the drill bit 100, as shown in Figure 9 . In a manner similar to that described above in Figure 7A , Figure 7B and Figure 8A , Figure 8B the lever lock 380 is depressed about the pivot 381 ( Figure 9 ) against the bias of the spring 387 to allow the surgeon to rotate and reorient the housing 320 to the final angular displacement position intended for the oscillatory movement of the drill bit 100 and then release the lever lock 380 into the opening 382a. When the motor 350 is activated, the gear assembly 340 and the linkage 344 cooperate to swing the oscillating gear 348 through a specific oscillating rotation angle β, which in turn causes the drill bit 100 to oscillate through a corresponding oscillating rotation angle Δ. In this particular case, at the final angular displacement position, the oscillating rotation angle of the oscillating gear is configured to be in the range of about 73° to about 85° or a predetermined maximum expected design angle, which in an embodiment can depend on the drill bit 100.

[0103] As described above, a change in the distance "H" between the axis OSA of the electric motor 350 and the axis SGA of the oscillating gear 348 causes a change in the oscillation angle β of the oscillating gear 348, which in turn causes a change in the corresponding oscillatory rotation angle Δ of the drill bit 100. In an embodiment, depending on the particular purpose, the gear ratio between the gear of the drive shaft 337 and the oscillating gear 348 for driving a surgical tool (e.g., the drill bit 100) can be in the range of about 1:1 or higher. In other embodiments, the ratio between the drive shaft gear 337 and the oscillating gear 348 is in the range of about 2:1. In still other embodiments, the ratio between the drive shaft 337 gear and the oscillating gear 348 is in the range of about 3:1. In yet other embodiments, the ratio between the drive shaft 337 gear and the oscillating gear 348 is in the range of about 3.88:1. In still other embodiments, the ratio between the drive shaft 337 gear and the oscillating gear 348 is in the range of about 4:1.

[0104] Now turning to Figures 10 to 14 , which shows the surgical device 300 set in a rotational mode that allows the drill bit 100 to perform a 360° full rotation about the drill bit axis. The full rotation of the drill bit 100 may be particularly suitable for incisive cutting, while the oscillation of the drill bit 100 may be better suited for finer tissue and bone shaving. The surgical device 300 enables a surgeon to easily switch between the two cutting modes (and with different cutting or shaving aggressiveness) without having to change the instrument or the drill bit 100.

[0105] If the surgeon wishes to switch the surgical device 300 from the oscillating mode to the rotational mode, the surgeon presses down on the lever lock 380 in a manner similar to that described above, and further rotates the housing 320 relative to the chuck 365 past the opening 382a (or in an embodiment, past the opening 382a in the opposite direction) to the rotational mode locking position, where the rotational locking opening 382R mechanically engages the lever lock 380 therein. While the housing 320 rotates past the opening 382a, the drive gear housing 390 is also toggled within the housing 320 to the rotational mode position, as shown by the arrow "RM" in Figure 10 .

[0106] More specifically, as best shown in Figure 12 , the drive gear housing 390 includes a shaft 393 that supports the oscillating gear 348, a shaft 333 that supports the idler gear 339, and a shaft 383 that supports the direct drive gear 387. The drive gear housing 390 further includes a post 392 that is configured to slide within a corresponding guide slot 363 defined within the distal end of the housing 320 ( Figure 11)。The pin slot 391 is defined within the side 390a of the drive gear housing 390a and is configured to limit the movement of the idler gear 339 to linear movement therein, such as "upward" and "downward" or "like a toggle". When the user rotates the lever lock 380 past the opening 382a and continues to rotate the housing 320, the post 392 slides along the slot 363 such that the housing 320 moves along the path of the post 392, which in turn causes its various internal gears (i.e., the oscillating gear 348, the idler gear 339, and the direct drive gear 387) to move along that path as the drive gear housing 390 moves. As the post 392 slides within the slot 363, the pin slot 391 restricts the movement of the entire drive gear housing 390 until the movement of the post 392 and the orientation of the pin slot 391 are substantially aligned, thereby allowing the drive gear housing 390 to move with the internal gearing disposed therein. At this first point along the path of the post within the slot 363, the oscillating gear 348 disengages from the gear of the drive shaft 337 to exit the oscillating mode. It is important to note that the link 344 remains connected to the gear output shaft 342 and moves the oscillating gear 348, but the oscillating gear 348 is no longer engaged with the gear of the drive shaft 337.

[0107] As the housing 320 rotates further and the post 392 moves further along the slot 363, the idler gear 339 engages the gear of the drive shaft 337 while remaining engaged with the distal end 387a of the direct drive gear 387 ( Figure 14 ). Additionally, as the post 392 moves within the slot 363 and the idler gear 339 engages the gear of the drive shaft 337, the proximal end 387b of the direct drive gear 387 simultaneously engages the distal end 342b of the gear output shaft 342. The proximal end 342a of the gear output shaft 342 engages the gear assembly 340, which in turn is connected to the motor 350 ( Figure 14 ). Once engaged, one or more pins 399 selectively lock the drive gear housing 390 in place. The surgical device 300 is now set in the rotational mode ( Figure 13 ), and the surgeon can use the same drill 100 to cut tissue or bone.

[0108] Returning to Figure 6C and Figure 6D, the exposure of the drill bit 100 can be controlled while maintaining the tool shaft 325 in the locked orientation as described above. More specifically, the proximal end 314 of the elongate tube 312 can be coupled to the housing 320 and positioned at the top of the tube 312 such that the elongate tube can be selectively rotated about the tube via the tool exposure mechanism 330 (similar to the tool exposure mechanism 30 described above). The inner perimeter of the proximal end 314 includes a helical groove 314a defined therealong, which is configured to receive the ball bearing 309 therein when the proximal end 314 is assembled on top of the tube 312. The outer perimeter of the tube 312 includes a pit 311a, which is configured to hold the ball bearing 309 therein such that the ball bearing extends partially out of the pit. When assembled, the ball bearing 309, the pit 311a, and the helical groove 314a are aligned such that rotation of the proximal end 314 fixed to the housing 320 forces the ball bearing 309 to move along the helical groove 314a, which in turn translates the tube 312 relative to the tool shaft 325 to vary the amount of exposure of the drill bit 100.

[0109] For example, rotation of the proximal end 314 in the direction Rew causes the ball bearing 309 to move distally along the track 314a, which in turn retracts the elongate tube 312 relative to the drill bit 100, increasing the tool exposure “E3” for surgical purposes (see arrow “RET”- Figure 6C ). Rotation of the proximal end 314 in the direction Rccw causes the ball bearing 309 to move distally along the groove 314a, which in turn extends the elongate tube 312 relative to the drill bit 100 to reduce the tool exposure “E4” for surgical purposes (see arrow “EXT”- Figure 6D ).

[0110] Returning to Figure 6E and Figure 6F, shows an alternative embodiment of a locking collar 370 for selectively engaging a surgical tool 100 within a housing 320 and includes a helical groove and bearing arrangement similar to that described above with respect to the tool exposure mechanism 330. More specifically, the locking collar 370 includes a helical groove 370a defined therein that extends along the locking collar and is configured to at least partially receive a ball bearing 372 therein. The chuck 35 is disposed within the distal end of the housing 320 and includes a pit 333a defined therein that is configured to receive the ball bearing 372 therein. The chuck 335 includes a locking bearing disposed therein that is configured to operably couple the distal end of the drive shaft 337 to the proximal end 325a of the tool shaft 325 when the distal end of the drive shaft 337 engages the proximal end 325a of the tool shaft 325. The distal end 337a of the drive shaft 337 and the proximal end 325a of the tool shaft 325 may include mechanical mating features, such as snap-fit members, keying, press-fit, tongue and groove, threaded fit, and ball and socket, etc., to facilitate their initial engagement, and these mechanical mating features may provide tactile feedback to the surgeon during loading and unloading of the tool shaft 325. In an embodiment, the distal end 337a of the drive shaft 337 includes a plurality of fork-like teeth 337a' that are spring-like configured to facilitate engagement with the proximal end 325a of the tool shaft 325. To load the tool shaft 325 into the surgical device 300, the locking collar 370 is rotated to the most proximal position, as Figure 6E shown. Then, the tool shaft 325 is inserted through the elongate tube 312 ( Figure 7B ) to engage the distal end 337a of the drive shaft 337 and is pushed to fully seat the proximal end 325a therein. Once in place, the locking collar 370 is rotated in the direction "L", which causes the helical ball 372 to move along the helical groove 370a, which in turn forces the chuck 335 to move distally. The distal end 337a of the drive shaft 337 remains stationary while the bearing 333 moves with the chuck 335 over the distal end 337a of the drive shaft 337, which clamps onto the proximal end 325a of the tool shaft 325 to secure the tool shaft 325 within the chuck 325. To release the tool shaft 325, the user simply rotates the locking collar 370 in the opposite direction and pulls the drill bit 100 and the tool shaft 325 from the distal end 337a of the drive shaft 337. A new drill bit 100 and tool shaft 325 may be replaced.

[0111] Now turning to Figures 15A to 16B, which shows an alternative embodiment of a gear assembly 540 for use with a surgical device 10 according to the present disclosure, the gear assembly enabling a user to switch between an oscillatory mode and a rotational mode. For the sake of brevity, only those aspects of the gear assembly 540 necessary to convey the operation of the gear assembly 540 are described in detail, however, it is contemplated that the gear assembly 540 may be configured to work with any one of the embodiments and / or components described above Figures 1 to 14 and work together.

[0112] More specifically, the gear assembly 540 includes a motor output shaft 542 that is configured to be operably coupled to an oscillating link 544 (as described above with respect to Figures 4A to 4C described) and a direct drive gear 587 (as described above with respect to Figure 14 described). The link 544, in turn, is connected at its opposite ends to a swing gear 548 that is configured to move into and out of engagement with a drive gear 565 that is common to the drive gear 587. The drive gear 587 is also configured to move into and out of engagement with the drive gear 565.

[0113] The drive gear 565 is disposed within the housing 520 and is movably coupled to the support chassis 570 such that when actuated, the drive gear 565 engages the swing gear 548 to oscillate the shaft 525 (as described in detail above with respect to Figures 1 to 14 described) or engages the drive gear 587 to rotate the shaft 525 fully (also as described above). The drive gear 565 also meshingly engages the proximal end 537 of the tool shaft 525. The guide plate 523 may be configured to align the axes of the respective gears 548, 565, and 587 within the housing 520 and guide the support chassis 570 during the transition between modes, and may be configured to rotate (or otherwise move) to a locked position to fix the gear assembly 540 to a selected operating mode, such as the oscillatory or rotational movement of the shaft 525. The outer ring 524 may be configured to lock the guide plate 523 in the respective oscillatory or rotational mode when it rotates, moves laterally, and / or moves longitudinally relative to the guide plate 523.

[0114] To switch between modes, the user moves the outer ring 524 relative to the housing 520 (via rotation or other movement), which, with the aid of the spring 572, moves the support chassis 570 and positions the swing gear 548 in engagement with the drive gear 565 or positions the direct drive gear 587 in engagement with the drive gear 565. Once in the desired operating mode, the user may lock either gear (gear 548 or gear 587) in the engaged state prior to activation.

[0115] During the transition between modes, one or more gears (e.g., one end of the drive gear 565 and the drive gear 587) may not be perfectly aligned before their engagement. To facilitate the engagement and proper meshing between the corresponding gear teeth (e.g., the drive gear 565 and / or the drive gear 587), one or both gears may include a chamfered surface 566' defined on one side of its corresponding gear tooth 566 ( Figure 17 ). The chamfered surface 566' can be cut, polished, honed, ground, or otherwise formed in each gear tooth 566 in any known manner in the art. It is contemplated that cutting the chamfered surface 566' at a smaller angle £ may be more beneficial for reducing the insertion force between the gear teeth of the drive gear 565 and the drive gear 587. Additionally, reducing the total surface area of one or both of the mating surfaces between the drive gear 565 and the drive gear 587 can also facilitate gear synchronization between modes. For example, the bottom surface area of the chamfered surface 566' ( Figure 17 ) of the drive gear 565 and the corresponding top surface area of the chamfered surface (not shown) of the drive gear 587 can be honed to a sharp edge to facilitate gear synchronization.

[0116] The chamfered surface 566' can extend along the length "gl" of each gear tooth 566 and be cut at an angle £, which can be in the range of about 5 degrees to about 35 degrees depending on the specific purpose. This can also facilitate gear synchronization between modes. In other embodiments, the angle £ can be in the range of about 20 degrees to about 35 degrees depending on the specific purpose to facilitate gear synchronization. In an embodiment, the angle £ can be in the range of about 5 degrees to about 20 degrees depending on the specific purpose to facilitate gear synchronization. Either or both of the drive gear 565 and the drive gear 587 can include chamfered surfaces 566', which independently or in combination facilitate gear synchronization.

[0117] Now turning to Figures 18A to 19B , which shows another embodiment of a gear assembly 640 for use with the surgical device 10 according to the present disclosure, the gear assembly enabling a user to switch between an oscillatory mode and a rotational mode. For the sake of brevity, only those aspects of the gear assembly 640 necessary to convey the operation of the gear assembly 640 are described in detail, however, it is contemplated that the gear assembly 640 can be configured to work with any of the above Figures 1 to 14 embodiments and / or components.

[0118] More specifically, the gear assembly 640 includes a motor output shaft 642, which is configured to be operatively coupled to the oscillating link 644 (as described above with respect to Figures 4A to 4C ) and the direct drive gear 687 (as described above with respect to Figure 14The connecting rod 644 is then connected at its opposite ends to a swing gear 648 which is configured to move into and out of engagement with a synchronizing gear 663 which in turn engages a drive gear 665. A drive gear 687 is configured to move into and out of engagement with a second synchronizing gear 661 which in turn jointly engages the drive gear 665.

[0119] The synchronizing gears 661 and 663 include proximally facing stop rings PR2, PR1 which are configured to engage corresponding distally facing stop rings DR2, DR1 provided on the drive gear 687 and the swing gear 648 when moved into engagement therewith. The drive gear 665 is disposed within the housing 620 and supported on the chassis 670. The guide plate 623 supports the synchronizing gears 661 and 663 on top of a spring 672 in a toggling-like manner such that when actuated only one gear (e.g., gear 661 or gear 663) engages the drive gear 665 to control movement of the shaft 625.

[0120] In an embodiment, the stop rings PR2, PR1 of the synchronizing gears 661 and 663 are configured to engage corresponding mating gears (i.e., the swing gear 648 for gear 663 and the drive gear 687 for gear 661), as well as corresponding distally facing stop rings associated with the drive gear 665 when actively engaged therewith, to transfer corresponding movement to the shaft 625. In other embodiments, the stop rings PR2, PR1 of the synchronizing gears 661 and 663 are configured to engage corresponding mating gears, i.e., the swing gear 648 for gear 663 and the drive gear 687 for gear 661, and the drive gear 665 includes a compound gear (not shown) associated with the drive gear 665 which engages when the corresponding synchronizing gears 661, 663 are actively engaged to transfer corresponding movement to the shaft 625. In other embodiments, one of the synchronizing gears (e.g., gear 663) may be configured to engage the proximal end 637 of the shaft 625 when engaged with the drive gear 665.

[0121] The drive gear 665 also meshingly engages the proximal end 637 of the tool shaft 625. The guide plate 623 may be configured to align the shafts of the corresponding gears 648, 665 and 687 within the housing 620. The outer ring 624 may be configured to lock the guide plate 623 in a corresponding oscillatory or rotational mode when it rotates, moves laterally and / or longitudinally relative to the guide plate 623.

[0122] To switch between modes, the user moves the outer ring 624 relative to the housing 620 (via rotation or other movement), which, with the assistance of the spring 672, moves the guide plate 623 and toggles the drive gear 665 that engages one of the synchronizing gears 661, 663, which respectively actuate the direct rotation drive gear 687 or the oscillating wobble gear 648. Once in the desired operating mode, the user can lock the gear (drive gear 687 or oscillating wobble gear 648) in the engaged state before enabling.

[0123] Now turning to Figures 20A to 24 , which shows an alternative embodiment of the oscillating mechanism according to the present disclosure, which can be used with any of the gear assemblies described above to oscillate the shaft of the surgical tool 100. More specifically, Figures 20A to 20F shows a gear-driven oscillating mechanism 900 according to one embodiment of the present disclosure, which includes a pair of opposing paddles 902 and 904 mounted on either side of a drive paddle 907 at the top of a drive rod 910, all of which are housed within a gear housing 920. The drive paddle 907 rotates 360° in the direction of arrow "DP" along the drive rod 910, which rotates 360° in the direction of arrow "DR" ( Figure 20A ). The opposing paddles 902 and 904 are fixed at the top of a common drive rod shaft 910a at their radially opposed ends and rotate towards each other in opposite directions without interfering with each other on either side of the paddle 907.

[0124] As the drive paddle 907 rotates through each 360° revolution, the drive paddle 907 will contact each respective paddle 902, 904 along a circumferential path. For example, as the drive paddle 907 rotates, the drive paddle 907 will initially contact the paddle 902 at the interference edge 902a and force both the paddle 902 and 904 to move with the drive paddle 907 in a first direction until the paddle 907 contacts the opposing paddle (e.g., paddle 904) at its interference edge 904a and forces both the paddle 902 and 904 to move with the drive paddle 907 in the opposite direction. This process is repeated, thereby causing an oscillatory motion of the drive rod shaft 910a in the direction of arrow "OS1" (see Figures 20B to 20F ).

[0125] Opposite sides of the paddle 902 define a rack 903a that is configured to engage a pinion 905a disposed on the oscillating shaft of the surgical tool 100. When the drive rod shaft 910a engages the pinion 905a, the oscillation of the drive rod shaft 910a is transmitted to the surgical tool 100. In an embodiment, the geometry of the paddles 902, 904, and / or 907 can be manipulated to vary the degree or angle of oscillation of the surgical tool 100 depending on the particular purpose.

[0126] Go to Figure 21 Figure 21 , which shows another embodiment of the gear-like oscillating mechanism 1000 according to the present disclosure. The oscillating mechanism 1000 includes a housing 1020 that is configured to support a plurality of shaft and gear assemblies arranged in parallel, the plurality of shaft and gear assemblies extending from a proximal motor input portion to a gear assembly output for oscillating a surgical tool 100. More specifically, a shaft 1007 supports the input portion from the motor and drives a first gear 1001 to rotate in a first direction FR1. The first gear 1001 meshes with a second gear 1003 that is mounted on top of a shaft 1005 and is configured to drive the second gear 1003 in an opposite direction FR2. Each gear 1001, 1003 includes a corresponding friction disk 1002, 1004 that is mechanically engaged to the respective shafts 1007, 1005 of each gear 1001, 1003. The friction disks 1002, 1004 include arcuate surfaces 1002', 1004' that extend beyond the outer perimeters of their respective gears 1001, 1003 such that each arcuate surface 1002', 1004' can frictionally engage the outer surface of the tool shaft 1010 during rotation of the tool shaft 1010. The arcuate surfaces 1002', 1004' are keyed on top of opposite sides of each respective shaft 1007, 1005 such that the respective arcuate surfaces 1002', 1004' do not contact each other during rotation but are marginally offset from each other during their co-rotation, thereby allowing each arcuate surface to alternately frictionally engage the tool shaft 1010. Through the alternating frictional engagement between two friction disks 1002, 1004 rotating in opposite directions, the shaft 1010 is forced to oscillate repeatedly as the friction disks 1002, 1004 continue to rotate.

[0127] For example, when the shaft 1007 rotates via the input portion from the motor, the two gears 1001, 1003 rotate, which correspondingly causes the friction disks 1002, 1004 to rotate. The friction disk 1002 rotates in the direction FR1 and contacts the shaft 1010 at point 1002a to correspondingly cause the shaft 1010 to rotate in the direction OF1. When the friction disk 1002 rotates beyond the trailing edge of the arcuate surface 1002' that engages the shaft 1010, the leading edge of the arcuate surface 1004' of the friction disk 1004 will timely engage the shaft 1010 and rotate in the reverse direction such that the shaft 1010 now rotates in the direction OF2. Similarly, when the friction disk 1004 rotates beyond the trailing edge of the arcuate surface 1004' that engages the shaft 1010, the leading edge of the arcuate surface 1002' of the friction disk 1002 will timely engage the shaft 1010 and rotate in the reverse direction such that the shaft 1010 rotates in the direction OF1 again. Repeating this process causes an oscillatory motion of the tool shaft 1010.

[0128] Go to Figure 22, which shows yet another embodiment of the gear-like oscillating mechanism 1100 according to the present disclosure. The oscillating mechanism 1100 includes a housing 1120 that is configured to support a plurality of shaft and gear assemblies arranged in parallel, the plurality of shaft and gear assemblies extending from a proximal motor input to a gear assembly output and then to an oscillating surgical tool 100. Generally, the oscillating mechanism 1100 operates in a manner similar to the oscillating mechanism 1000, except that the oscillating mechanism utilizes a pair of partially compound gears 1102, 1104 that are configured to engage a common gear 1109 disposed on the shaft 1110 of the surgical tool 100. An initial input from the motor causes the gear 1102 to rotate in a first direction, which in turn causes the gear 1109 and the shaft 1110 to rotate in the same direction until the partially compound geometry of the gear 1102 disengages the gear 1109 from the gear 1102 and engages the gear 1109 with the gear 1104 during the range of motion, thereby reversing the direction of the gear 1109 and the shaft 1110. The gear 1102 and the motor input continue to rotate in the same direction. When the gear 1104 continues to rotate the gear 1109 and the shaft 1110 in the same direction, the partially compound geometry of the gear 1104 disengages the gear 1109 from the gear 1104 and again reverses the direction of the gear 1109 and the shaft 1110 to engage the gear 1102. The gear 1102 continues to rotate in the same direction. This process is repeated, thereby causing an oscillatory motion of the tool shaft 1010.

[0129] In an embodiment, one or more of the above oscillating mechanisms may be used in conjunction with an oscillation enhancement mechanism or an oscillation "amplification" mechanism that is configured to increase the oscillation angle of the surgical tool 100 (see Figure 23 ). More specifically, an input from the motor shaft 1305 may be fed into any one of the above oscillating mechanisms (e.g., the oscillating mechanism 1304) to produce an initial oscillation angle (for the purposes of this article, within a range of about 5° output to the tool shaft 1310). The oscillation enhancement tool 1300 may be operatively engaged to the tool shaft 1310, and

[0130] is configured to increase the oscillation angle of the tool to an oscillation angle within a range of about 50° to about 90°. By simply using the motor input of the tool shaft as the above motor input, any one of the above gear assemblies and oscillating mechanisms may be utilized to achieve this purpose. The enhancement tool 1300 may be operatively coupled to one or more gears 1215 (or gear assemblies) disposed within the housing 1220 of the instrument 1200 and output to the surgical tool 1210.

[0131] Turning to Figure 24, which shows yet another embodiment of the oscillating mechanism 1400 according to the present disclosure. The oscillating mechanism 1400 includes a housing 1420 that is configured to support a plurality of shaft and gear assemblies arranged in parallel, the plurality of shaft and gear assemblies extending from a proximal motor input to a gear assembly output and then to a surgical tool 100 that oscillates similar to the above-described surgical instrument. In this case, the motor 1450 is configured to output a reciprocating motion LR to the shaft 1410 similar to a reciprocating saw or similar to some known ultrasonic surgical platforms. With the arrangement of the helical groove 1417 and the pin 1415 disposed within the housing 1420, the reciprocating motion of the shaft 1410 is converted into an oscillating motion of the tool shaft 1412 (see arrow OS3).

[0132] More specifically, the distal end of the shaft 1410 is operatively coupled to the pin 1415 such that the pin 1415 reciprocates synchronously therewith. The pin 1415 is in turn configured to slide within the helical groove 1417 that is operatively associated with the shaft 1412 such that the longitudinal reciprocating motion of the pin 1415 within the groove 1417 causes the shaft 1412 to oscillate, as shown by arrow OS3. The oscillation of the shaft 1412 is transmitted to the surgical tool 100 for a particular surgical purpose.

[0133] Although multiple aspects of the present disclosure have been shown in the drawings, it is not intended to limit the present disclosure to these aspects, as the present disclosure is intended to be as broad as permitted in the art and the specification should be interpreted in the same manner. Accordingly, the above description should not be construed as limiting, but merely as an illustration of a particular configuration. Those skilled in the art can envision other modifications within the scope and spirit of the appended claims herein.

[0134] It should be understood that various modifications can be made to the aspects and features disclosed herein. Accordingly, the above description should not be construed as limiting, but merely as examples of the various aspects and features. Those skilled in the art can envision other modifications within the scope and spirit of the appended claims herein.

Claims

1. A surgical device for cutting or shaving bone or hard tissue, the surgical device comprising: An outer housing having a chuck fixed to an inner circumferential surface of the outer housing, the chuck including a series of openings defined around a circumference in the chuck; A housing including an elongate tube extending from the housing, the elongate tube being configured to support a surgical tool at a distal end of the elongate tube; A gear assembly disposed within the housing and configured to drive the surgical tool, the gear assembly including a drive gear housing that is selectively movable within the housing to switch the gear assembly between an oscillating mode and a rotating mode to drive the surgical tool; And A motor operably coupled to the gear assembly such that upon activation of the motor, the motor performs at least one of oscillating or rotating the surgical tool depending on the position of the drive gear housing within the housing.

2. The surgical device for cutting or shaving hard tissue according to claim 1, wherein the housing includes a slot defined in a proximal end of the housing, the slot communicating with a post extending from the drive gear housing such that upon movement of the housing, the slot correspondingly moves the post within the slot.

3. The surgical device for cutting or shaving hard tissue according to claim 2, wherein the slot is arcuate and the post moves within the slot as the housing rotates relative to the chuck.

4. The surgical device for cutting or shaving hard tissue according to claim 3, the surgical device further comprising a lever lock operatively coupled to the housing, and wherein, Upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck, and upon release, the lever lock allows the user to lock the lever lock in one of the series of openings defined within the chuck.

5. The surgical device for cutting or shaving hard tissue according to claim 1, wherein when set to the oscillating mode, the gear assembly operably engages a link that oscillates a swing gear by a rotational angle β that depends on a distance between an axis of the motor and an axis of the swing gear.

6. The surgical device for cutting or shaving hard tissue according to claim 5, wherein, The distance between the axis of the motor and the axis of the swing gear changes as the housing rotates relative to the chuck, thereby changing the rotational angle β.

7. The surgical device for cutting or shaving hard tissue according to claim 5, the surgical device further comprising a lever lock operatively coupled to the housing, and wherein, Upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck, and upon release, the lever lock allows the user to lock the lever lock in one of the series of openings defined within the chuck, and wherein each of the series of openings sets the rotational angle β of the swing gear.

8. The surgical device for cutting or shaving hard tissue according to claim 7, wherein at least one of the series of openings defines the rotational angle β of the swing gear as being approximately 59°, approximately 68°, or approximately 76°.

9. A surgical device for cutting or shaving bone or hard tissue, the surgical device comprising: An outer housing having a chuck fixed to an inner circumferential surface of the outer housing, the chuck including a series of openings defined about a circumference in the chuck; A housing including an elongate tube extending from the housing, the elongate tube configured to support a surgical tool at a distal end of the elongate tube; A gear assembly disposed within the housing and configured to drive the surgical tool, the gear assembly including a drive gear housing that is selectively movable within the housing to switch the gear assembly between an oscillating mode and a rotational mode to drive the surgical tool; and A motor operably coupled to the gear assembly such that upon activation of the motor, the motor performs at least one of oscillating or rotating the surgical tool depending on a position of the drive gear housing within the housing, wherein when set to the rotational mode, the gear assembly operably engages a direct drive gear that is coupled to an idler gear driving the surgical tool.

10. The surgical device for cutting or shaving hard tissue according to claim 9, wherein the housing includes a slot defined in a proximal end of the housing, the slot in communication with a post extending from the drive gear housing such that upon movement of the housing, the slot correspondingly moves the post within the slot.

11. The surgical device for cutting or shaving hard tissue according to claim 10, wherein the slot is arcuate and the post moves within the slot as the housing rotates relative to the chuck.

12. The surgical device for cutting or shaving hard tissue according to claim 11, the surgical device further comprising a lever lock operatively coupled to the housing, and wherein, Upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of the series of openings defined within the chuck.

13. The surgical device for cutting or shaving hard tissue according to claim 12, wherein, Upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck and, upon release, the lever lock allows the user to lock the lever lock in one of the series of openings defined within the chuck, and wherein rotation of the housing to one of the series of openings subsequently moves the drive gear housing to configure the surgical device to the rotational mode.

14. The surgical device for cutting or shaving hard tissue according to claim 13, wherein as the housing rotates relative to the chuck, the post moves along the slot to disengage from a series of gears associated with the oscillating mode and engage a series of gears associated with the rotational mode.

15. The surgical device for cutting or shaving hard tissue according to claim 14, wherein the drive gear housing includes a pin slot defined in the drive gear housing, the pin slot configured to at least partially seat the idler gear within the pin slot, the pin slot configured to limit movement of the drive gear housing in a linear direction as the housing rotates.

16. A surgical device for cutting or shaving bone or hard tissue, the surgical device comprising: An outer housing having a chuck fixed to an inner circumferential surface of the outer housing, the chuck including a series of openings defined about a circumference in the chuck; A housing including an elongate tube extending from the housing, the elongate tube being configured to support a surgical tool at a distal end of the elongate tube; A gear assembly disposed within the housing and configured to drive the surgical tool, the gear assembly including a drive gear housing that is selectively movable within the housing to switch the gear assembly between an oscillatory mode and a rotational mode to drive the surgical tool; and A motor operably coupled to the gear assembly such that upon startup of the motor, the motor performs at least one of oscillating or rotating the surgical tool depending on a position of the drive gear housing within the housing, wherein when set to the rotational mode, the gear assembly operably engages a direct drive gear that is coupled to an idler gear driving the surgical tool, wherein when set to the oscillatory mode, the gear assembly operably engages a linkage that oscillates a swing gear by a rotational angle β that depends on a distance between an axis of the motor and an axis of the swing gear.

17. The surgical device for cutting or shaving hard tissue according to claim 16, wherein the housing includes a slot defined in a proximal end of the housing, the slot being in communication with a post extending from the drive housing such that as the housing moves, the slot correspondingly moves the post within the slot.

18. The surgical device for cutting or shaving hard tissue according to claim 17, wherein, The slot is arcuate, and the post moves within the slot as the housing rotates relative to the chuck.

19. The surgical device for cutting or shaving hard tissue according to claim 18, the surgical device further comprising a lever lock operatively coupled to the housing, and wherein, Upon actuation, the lever lock allows a user to selectively rotate the housing relative to the chuck, and upon release, the lever lock allows the user to lock the lever lock in one of the series of openings defined within the chuck.

20. The surgical device for cutting or shaving hard tissue according to claim 16, wherein the surgical tool includes a drill bit configured to cut or shave tissue when set to the oscillatory mode or the rotational mode.

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