Patent Description:
Rotary tools are often used in many fields for precise applications. The spectrum of bases, mounts and handles for interchangeable tools is broad. A commonality on both mechanical and powered devices or bases is the ability to mount and unmount a tool. The bases or handles may be fixed wherein t e base provides on a fixation point, other bases may include additional mechanism for any or ratcheting, torque control and the like. There are shortcomings with conventional connecting mechanisms. First, existing devices have many separate components. This makes them difficult to assemble and costly to manufacture. Second, existing options which are intended for many repetitive uses and require proper maintenance and sterilizations between uses. In medical uses, they may contact dangerous medical waste, requiring extensive cleaning and sterilization and carrying an inherently higher risk of contamination. Therefore, there is a need for an improved retention assembly for connecting a tool. <CIT> discloses the preamble of claim <NUM> and <NUM> and describes a chuck mechanism for a dental handpiece and a dental handpiece with the chuck mechanism. This chuck mechanism holds the columnar rotary tool for dental care rotatably with an annular rotor of the dental handpiece and the columnar rotor tool is concentrically detachable to the annular rotor which is rotatably attached to a head part of the dental handpiece. The chuck mechanism is characterized by an annular chucking member which comprises a cylindrical base part into which the annular rotor is integrally fitted and an elastic chucking piece having a chucking pawl for engaging with a locking groove formed at a base end of the rotary tool. The chuck mechanism enables the rotary tool to be easily removed from the annular rotor by elastically deforming the elastic chucking piece against elastic force of the elastic chucking piece to disengage the chucking pawl from the locking groove. <CIT> describes a tool bit and collet assembly, and method of assembling, wherein there is a collar for holding the collet in the radially inward position to thereby hold the tool bit. Camming surfaces are between the tool bit and the collet, and between the collet and the collar, for opening the collet upon insertion the tool bit into the collet, and thereby move the collar to the opening position.

The foregoing needs are met by the various aspects of retainer assemblies disclosed. A retention assembly for connecting a base to a tool having a shaft can include a shaft engagement socket that defines a shaft receptacle configured to receive the shaft along an insertion axis. The retention assembly includes a retainer configured to releasably securethe shaft to the shaft engagement socket. The retainer has a body that defines an opening extending therethrough, with the opening being dimensioned to receive the shaft. The retention assembly further includes at least one finger extending from the body of theretainer.

In some non-limiting aspects, the at least one finger may define a sliding surface and be configured to contact the shaft. The sliding surface of the at least one finger may be configured to slidably contact a ramp on the shaft engagement socket.

The retainer is movable relative to the shaft engagement socket along the insertion axis, such that when the retainer is translated toward the shaft engagement socket, the sliding surface of the at least one finger slides along the ramp of the shaft engagement socket and causes the at least one finger to move away from the shaft, and when the retainer is translated away from the shaft engagement socket, the sliding surface of the atleast one finger slides along the ramp and causes the at least one finger to move towards the shaft.

According to a non-limiting aspect of the disclosure, the at least one finger may include a protrusion between the sliding surface and the body of the retainer. The protrusion may extend from the at least one finger towards the insertion axis and be configured to be received within a notch on the shaft. When the protrusion is in the notch, the shaft may be precluded from moving along the insertion axis. This would help solve the problem of an unsecured shaft or of a shaft that is accidentally or inadvertently removed fromthe retention assembly.

According to a non-limiting aspect, the retainer may include an outer wall extending from the body and an attachment clip disposed on the outer wall. The attachment clip may be configured to slidably engage the shaft engagement socket to releasably secure the retainer to the shaft engagement socket. The retainer may be removed from the rest of the device and used reused later or disposed of. Removing the retainer may help reduce contamination from improperly cleaned retainers by allowing the retainer to be cleaned or replaced.

In some non-limiting aspects, the body of the retainer may include a cutout between the at least one finger and the outer wall.

According to some aspects, the body may include a plurality of cutouts between the at least one finger and the outer wall.

According to a non-limiting aspect, the shaft engagement socket may include at least one wall configured to contact a locking surface on a socketing region of the shaft when the socketing region is in the shaft engagement socket. When the wall is in contact with the locking surface, rotational movement of the shaft around the insertion axis may be precluded. This may be advantageous to properly impart rotational force from the base or another rotary mechanism configured to rotate the shaft.

In some aspects, the socketing region of the shaft may have a semi-circular cross section.

In some aspects, the shaft engagement socket may include four walls, each wall being orthogonal to two adjacent walls. The four walls may define the shaft receptacle that is configured to receive the shaft. The proximal end of the shaft may have a rectangular cross section in this aspect.

According to a non-limiting aspect, the at least one finger of the retention assembly may be deformable, such that when the retainer is translated towards the shaft engagement socket, the at least one finger deflects radially away from the insertion axis.

In some aspects, the protrusion may be triangular, and the notch on the shaft may also be triangular.

In other aspects, the protrusion may be arcuate, and the notch on the shaft may be arcuate.

In a non-limiting aspect, the retainer may include a plurality of fingers as described herein.

In some aspects, the retainer may include at least three fingers.

In some aspects, the retainer may include four fingers.

According to a non-limiting aspect, the shaft engagement socket may define a radial channel having a floor and a ceiling. The radial channel may be configured to receive the attachment clip therein. The attachment clip may be movable within the channelbetween the floor and the ceiling, such that the movement of the retainer towards the shaft engagement socket is confined by contact between the attachment clip and the ceiling, and movement away from the shaft engagement socket is confined by contact between the attachment clip and the floor.

According to a non-limiting aspect, the retainer may define a guide configured to contact the shaft and to align the shaft to a permitted orientation. The shaft may be precluded from moving through the retainer if the shaft is not in the permitted orientation. This may help reduce improper insertion of the shaft into the retention assembly and can also reduce instances of damage to the shaft or to the retainer. This would reduce associated manufacturing costs and preparation time during use.

In some non-limiting aspects, the tool having the shaft that is connected to the retention assembly may be a medical device.

In some non-limiting aspects, the retainer may be disposable and unsuitable for heat sterilization.

According to an aspect of the disclosure, a method of connecting a tool having a shaft to a base may include the step of inserting a shaft into an opening defined by a retainer. The retainer has at least one finger configured to contact the shaft. The method further includes the step of moving the at least one finger away from the shaft such that the shaft passes through the opening of the retainer and towards a shaft engagement socket. The method further includes the step of inserting the shaft into a shaft receptacle defined by the shaft engagement socket. The method also includes securing the shaft within the shaft receptacle by moving the at least one finger towards the shaft such that the at least one finger precludes translation of the shaft along the insertion axis.

The method further includes the step of moving the retainer in a first direction along the insertion axis toward the shaft engagement socket, such that the at least one finger is moved away from the shaft.

According to a non-limiting aspect, the method may further include the step of sliding the at least one finger along a ramp defined by the shaft engagement socket when the retainer is moved along the insertion axis.

According to a non-limiting aspect, the method may further include removing the shaft from the base. The removal step may include moving the at least one finger away from the shaft and moving the shaft out of the shaft receptacle and away from the shaft engagement socket.

In some aspects, the method may include a further step of precluding rotational movement of the shaft when the shaft is within the shaft receptacle. This may be performed by contacting a wall defined by the shaft receptacle with a corresponding locking surface on the shaft. This may be advantageous to properly impart rotational force from the base or another rotary mechanism configured to rotate the shaft.

According to a non-limiting aspect, the method may further include the step of orienting the shaft to a permitted orientation by contacting the shaft to a guide defined on the retainer. This may help reduce improper insertion of the shaft into the retention assembly and can also reduce instances of damage to the shaft or to the retainer. This would reduce associated manufacturing costs and preparation time during use.

According to a non-limiting aspect, the method may further include a step of contacting a protrusion extending from the at least one finger with a notch defined on the shaft. When the at least one finger is moved away from the shaft, the protrusion is also moved out of the notch, and when the at least one finger is moved toward the shaft, the protrusion is moved into the notch.

According to a non-limiting aspect of the present disclosure, a retention assembly for connecting a base to a tool having a shaft may include a shaft engagement socket having four walls, each wall being orthogonal to two adjacent walls. The four walls may define a shaft receptacle. The shaft engagement socket may be configured to receive the shaft of the medical tool. In some instances the shaft engagement socket may be configured to correspond to the cross section of the shaft. The shaft has a proximal end and a distal end opposite the proximal end and defines an insertion axis extending between the proximal end and the distal end. The shaft receptacle of the shaft engagement socket may be dimensioned to slidably receive the proximal end of the shaft therein. A retainer may be configured to removably secure the shaft to the socket. The retainer may have a body that defines an opening extending therethrough, the opening being dimensioned to receive the proximal end of the shaft therein. The retainer further may have an outer wall extending from the body. Adeformable clip may be disposed on the outer wall and be configured to slidably engage the shaft engagement socket to releasably secure the retainer to the shaft engagement socket. The deformable clip may be deformable in a direction orthogonal to the insertion axis. A finger may be disposed on the inner wall and configured to deflect away from the insertion axis. The finger may define a sliding surface and a protrusion disposed between the contact surface and the body of the retainer. The protrusion may extend from the finger towards the insertion axis and be configured to contact a notch defined on the shaft. A guide may be disposed on the retainer. The guide may be configured to contact the shaft and to orient the shaft to a permitted orientation. The guide may preclude the shaft from moving into the retainer if the shaft is not in the permitted orientation. Each wall of the shaft engagement socket may define a ramp configured to slidably contact the contact surface of the finger. The retainer is configured to translate relative to the shaft engagement socket along the insertion axis. When the retainer is translated toward the shaft engagement socket, the sliding surface of the finger slides along the ramp of the shaft engagement socket and causes the finger to deflect away from the insertion axis. The proximal end of the shaft may define a rectangular cross section and may be insertable into the shaft receptacle of the shaft engagement socket, such that when the proximal end is in the shaft receptacle, rotational movement of the shaft about the insertion axis is impeded.

The present application is further understood when read in conjunction with the appended drawings. For the purpose of illustrating the subject matter, there are shown in the drawings exemplary embodiments of the subject matter; however, the presently disclosed subject matter is not limited to the specific methods, devices, and systems disclosed. In the drawings:.

Aspects of the disclosure will now be described in detail with reference to the drawings, wherein like reference numbers refer to like elements throughout, unless specified otherwise.

Bases which hold tools are used across various industries, including medical. The tools often need to be connected or disconnected. The bases include the full spectrum of devices from fixed to rotating, including but not limited to ratcheting, drills, motors, and torque limiting. A base can have a retention assembly attached thereto that serves to connectand disconnect a desired tool. While torque-limiting devices are exemplified throughout this disclosure, it will be understood that such an engagement assembly is not limited only to torque-limiting devices, but also includes other bases and devices and other power or rotary tools and apparatuses used in tool automation. Similarly, this disclosure is not limited to any particular tool that is connected to the base, and it will be appreciated that any rotational tool can be implemented, such as a drill, driver, cutter, grinder, sander, or another rotational apparatus.

Referring to <FIG>, a device <NUM> includes a retention assembly <NUM> that is configured to receive and interact with a tool having a shaft <NUM>. The shaft <NUM> can be inserted into the retention assembly <NUM> and releasably secured therein. While secured by the retention assembly <NUM>, the shaft <NUM> can receive rotational force from the torque-limiting device <NUM> and further impart that force onto the connected tool (not shown). The shaft <NUM> hasa proximal end <NUM> and a distal end <NUM> opposite the proximal end <NUM>. The shaft <NUM> can be connected to a rotational tool (not shown) at the distal end <NUM>. A socketing region <NUM> is defined along the shaft closer to the proximal end <NUM> than to the distal end <NUM>. The socketing region <NUM> may be directly adjacent to the proximal end <NUM>.

With reference to <FIG>, the retention assembly <NUM> has a shaft engagement socket <NUM> that is configured to retain the shaft <NUM> and to provide an interface between the shaft <NUM> and the base <NUM>. The shaft engagement socket <NUM> includes at least one wall <NUM> that defines a shaft receptacle <NUM>, into which the proximal end <NUM> of the shaft <NUM> can be inserted along an insertion axis A. The shaft engagement and the shaft are configured to provide a shape for the shaft engagement which receives a cross-section of the shaft. The shaft may be circular, D-shaped (semi-circular), hexagon, polygon or another shape formed in cross section on a shaft. In some aspects, the shaft receptacle <NUM> may be defined by a plurality of walls <NUM> arranged in an advantageous geometric shape. For example, the shaft engagement socket <NUM> may include four walls <NUM>, with each wall being disposed orthogonally to each adjacent wall such that the defined shaft receptacle <NUM> has a square cross section. The cross section of the shaft receptacle <NUM> may complement that of the socketing region <NUM> of the shaft <NUM>. While square cross sections are exemplified, it will be appreciated by persons skilled in the art that other suitable shapes can be used, such as semi-circles, rectangles, pentagons, hexagons, or other polygons. The socketing region <NUM> may include at least one locking surface <NUM> configured to contact the wall <NUM> when the shaft <NUM> is in the shaft receptacle <NUM>. The cross section of the shaft receptacle <NUM> may be the same shape as that of the socketing region <NUM>, but that is not a requirement.

When rotational force is imparted by the base <NUM> or by another driver to the shaft <NUM>, it is advantageous to prevent the shaft <NUM> from rotating freely within the shaft receptacle <NUM> or to prevent the shaft engagement socket <NUM> from rotating freely around the shaft <NUM> without imparting the desired rotational force. Contact between at least one wall <NUM> and at least one locking surface <NUM> is configured to confine the link the rotation of the shaft <NUM> with that of the shaft engagement socket <NUM>.

To prevent the shaft <NUM> from being inadvertently removed from the shaft engagement socket <NUM>, a retainer <NUM> secures the shaft <NUM> within the shaft receptacle <NUM>. Referring to <FIG>, the retainer <NUM> has a body <NUM> that defines an opening <NUM> therethrough. The opening <NUM> is dimensioned such that at least a portion of the shaft <NUM>, including at least the socketing region <NUM>, can be inserted through it. The retainer <NUM> includes at least one finger <NUM> that surrounds the opening <NUM>. The finger <NUM> is configuredto engage with the shaft <NUM> and to prevent the shaft <NUM> from being removed from the shaft receptacle <NUM>.

The finger <NUM> extends from the body <NUM> and includes a sliding surface <NUM> and a protrusion <NUM> between the sliding surface <NUM> and the body <NUM>. The retention assembly <NUM> may include any suitable number of fingers <NUM>, for example, <NUM>, <NUM>, <NUM>, <NUM>,. , or20 fingers <NUM>.

Each finger <NUM> can be configured to move toward and away from the insertion axis A as the shaft <NUM> is inserted into or removed from the shaft engagement socket <NUM>. The finger <NUM> may include an elastically deformable material and may be permanently attached to, or be a unitary part of, the retainer body <NUM>. As a force is applied to the finger <NUM> radially away from the insertion axis A, the finger <NUM> may remain fixed to or a part of the body <NUM>, while the sliding surface <NUM> and the protrusion <NUM> may be deflected radially away from the insertion axis A. When the force is removed, the finger <NUM> reverts to its previous non-deflected state, and the sliding surface <NUM> and the protrusion <NUM> are moved radially toward the insertion axis A.

In some aspects, the finger <NUM> may be a non-unitary part that is separated from the body <NUM> and is moveably attached thereto. In such aspects, when the force is applied radially away from the insertion axis A, the finger <NUM> slidably moves along the body154 such that the sliding surface <NUM> and the protrusion <NUM> are moved away from the insertion axis A. A biasing mechanism may be disposed between the finger <NUM> and the body154, such that when the force is removed from the finger, the biasing mechanism moves the finger <NUM> back towards the insertion axis A. The biasing mechanism may be a helical spring, a deformable rod, or another mechanism configured to provide a biasing force againstthe finger <NUM> from the body <NUM>.

The finger <NUM> may contact the shaft <NUM> to prevent the shaft <NUM> from being moved out of the shaft engagement socket <NUM>. The shaft <NUM> may define a notch <NUM> that is configured to receive the protrusion <NUM> of the finger <NUM>. The notch <NUM> may be a radial notch that extends around the circumference of the shaft <NUM>. Alternatively, the notch <NUM> maybe defied on a portion of the shaft <NUM> and not extend circumferentially around the shaft <NUM>. The shaft <NUM> may include a plurality of notches <NUM>. In some aspects, the number of notches <NUM> may be the same as the number of fingers <NUM>.

The notch <NUM> may be arcuate and may complement the protrusion <NUM>, such that the protrusion <NUM> may be moved into the notch <NUM>. It will be appreciated that the specific dimensions of the notch <NUM> are not limited by this disclosure, and other shapes can besuitable, for example, triangular, square, semi-circular, or other shapes. The protrusion <NUM> may similarly include any suitable shape, for example, semi-circular, triangular, quarter- circular, or another suitable shape. While the protrusion <NUM> can be dimensioned to complement the notch <NUM>, this is not a requirement. The specific dimensions of the notch <NUM> can vary, but it will be understood that the largest cross-sectional measurement of the shaft <NUM> at the notch <NUM> is smaller than the largest cross-sectional measurement of the shaft <NUM> between the notch <NUM> and the proximal end <NUM>. For example, in shafts having a round cross section, the largest cross-sectional measurement is the diameter.

The notch <NUM> may be disposed between the proximal end <NUM> and the distal end <NUM>. In some aspects, the notch <NUM> may be adjacent to the socketing region <NUM>. As exemplified in <FIG>, the notch <NUM> may be located along the shaft <NUM> between the socketing region <NUM> and the distal end <NUM>.

When the protrusion <NUM> is within the notch <NUM>, axial movement of the shaft <NUM> along the insertion axis A is precluded. This helps prevent the shaft <NUM> and the tool to which it is attached (not shown) from being removed from the shaft engagement socket <NUM>. This decreases damage to the tool, injury to the user, and any preparation time required to reinsert or correct alignment of the tool in the retention assembly <NUM>.

The retainer <NUM> is configured to permit the shaft <NUM> to pass along a first direction along the insertion axis A towards the shaft engagement socket. Referring to <FIG>, as the shaft <NUM> is moved into the opening <NUM> of the retainer <NUM>, the shaft <NUM> contacts the finger <NUM>. This contact may occur at the proximal end <NUM> or at another location along the shaft <NUM> between the proximal end <NUM> and the notch <NUM>. The shaft <NUM> may contact the protrusion <NUM> on the finger <NUM>. As the shaft <NUM> moves through the opening <NUM>, a force is exerted on the finger <NUM> radially away from the shaft <NUM> and the insertion axis A. This force results in the deflection of the finger <NUM> as described above. Referring now to <FIG>, as the shaft <NUM> is moved further towards the shaft engagement socket <NUM>, the socketing region <NUM> ispositioned within the shaft receptacle <NUM>. When the socketing region <NUM> is in the shaft receptacle <NUM>, the notch <NUM> contacts the finger <NUM>, preferably at the protrusion <NUM>. The protrusion <NUM> disposed in the notch <NUM> prevents the shaft <NUM> from being moved in a second direction opposite the first direction and out of the shaft receptacle <NUM>.

To remove the shaft <NUM> from the shaft receptacle <NUM>, the finger <NUM> is deflected radially such that the shaft <NUM> does not contact the finger <NUM>. The finger <NUM> may be deflected such that the protrusion <NUM> is moved out of the notch <NUM>. After the finger <NUM> is moved away from the shaft <NUM>, the shaft <NUM> is permitted to move axially along the insertion axis A and can be removed from the shaft engagement socket <NUM> and out of the retainer <NUM> through the opening <NUM>.

The finger <NUM> may be deflected by an actuator, such as a button or a lever. In some aspects, the finger <NUM> may be pushed radially away from the insertion axis A by another component of the retention assembly <NUM>. In some aspects, the retainer <NUM> may be movable axially along the insertion axis A toward and away from the shaft engagement socket. As shown in <FIG>, the retainer <NUM> may have a locking position when the retainer <NUM> is at a first distance D1 away from the shaft engagement socket. Referring to <FIG>, the retainer <NUM> may have an unlocking position when the retainer <NUM> is at a second distance D2away from the shaft engagement socket. The second distance is smaller than the first distance. When the retainer <NUM> is in the locking position and the shaft <NUM> is inserted in the shaft receptacle <NUM>, the finger <NUM> contacts the shaft <NUM> and prevents the shaft <NUM> from beingremoved from the shaft receptacle <NUM>. When the retainer <NUM> is in the unlocking position, the finger <NUM> is deflected away from the shaft <NUM> and the shaft <NUM> can be axially moved out of the shaft receptacle <NUM>.

Referring to <FIG>, the shaft engagement socket <NUM> may include a ramp <NUM> configured to slidably contact the sliding surface <NUM> of the finger <NUM>. The ramp <NUM> has a proximal end 116a and a distal end 116b opposite the proximal end 116a. The ramp <NUM> is oriented such that the distal end 116b is closer to the insertion axis A than the proximal end 116a. When the retainer <NUM> is moved from the locking position to the unlocking position, the sliding surface <NUM> contacts the ramp <NUM>, and the finger <NUM> slides along the ramp <NUM> toward the proximal end 116a. As the finger <NUM> slides along the ramp <NUM>, the finger <NUM> is deflected radially away from the insertion axis A and away from the notch <NUM>. To move the retainer <NUM> to the locking position, the retainer <NUM> may be translated in the second directionaway from the shaft engagement socket <NUM> such that the finger <NUM> slides along the ramp <NUM> towards the distal end 116b.

In some aspects, a biasing mechanism may be disposed between the retainer <NUM> and the shaft engagement socket <NUM>. The biasing mechanism may be a spring, a deformable rod, or another suitable mechanism that is configured to provide a biasing force. The retainer <NUM> may be biased toward the locking position, such that moving the retainer <NUM> from the locking position to the unlocking position requires overcoming the biasing force exerted by the biasing mechanism on the retainer.

In some aspects, the finger <NUM> acts as the biasing mechanism. When the sliding surface <NUM> is moved along the ramp <NUM> towards the proximal end 116a, the finger <NUM> is deflected. The finger <NUM> may be biased against this deflection such that the retainer <NUM> is configured to move from the unlocking position to the locking position absent a suitable force exerted on the retainer <NUM> to move the retainer <NUM> to the locking position or keep the retainer <NUM> in the locking position.

The retainer <NUM> may be attached to the shaft engagement socket <NUM> via any suitable method that permits axial movement of the retainer <NUM> relative to the shaft engagement socket <NUM> along the insertion axis A. The retainer <NUM> may have an outer wall <NUM> extending from the body <NUM>. The outer wall <NUM> may include an attachment clip <NUM> configured to engage with the shaft engagement socket <NUM>. The attachment clip <NUM> is an exemplary only, and a snap-in or removable fit is not an exclusive means of attachment. The attachment clip <NUM> may or may not have one or more heads <NUM>. An exemplary attachment clip <NUM> without heads is depicted in <FIG>. In some aspects, the outer wall <NUM> may definea plurality of attachment clips <NUM> disposed around the circumference of the retainer <NUM>.

The shaft engagement socket <NUM> may define a channel <NUM> configured to receive the attachment clip <NUM>. The channel <NUM> has a floor <NUM> and a ceiling <NUM>. The attachment clip <NUM> has a head <NUM> disposed within the channel <NUM> and configured to move between the floor <NUM> and the ceiling <NUM>. The channel <NUM> may be a continuous channel that surrounds the shaft engagement socket <NUM>, and the attachment clip <NUM> may be configured to move within the channel <NUM> around the insertion axis A. This would permit the retainer <NUM> to rotate freely around the insertion axis A.

The attachment clip <NUM> may be removed from the channel <NUM> such that the retainer <NUM> is separated from the shaft engagement socket <NUM>. The attachment clip <NUM> may be deflected toward the insertion axis A such that the head <NUM> can be removed from within the channel <NUM> through a channel opening <NUM> between the channel floor and the insertion axis A. Alternatively, if the channel floor <NUM> is between the channel opening <NUM> and the insertion axis A, the attachment clip <NUM> may be deflected away from the insertion axis A such that the head <NUM> can be removed from the channel <NUM>.

The shaft engagement socket <NUM> defines a first interface <NUM> shown as a circumferential end that is configured to engage a second interface <NUM> disposed on the retainer <NUM> between the heads <NUM>. In some instances, the retainer <NUM> does not have any heads <NUM>, and the first interface <NUM> can interface with the second interface <NUM> circumferentially as depicted in <FIG> and <FIG>.

As described above, the retainer <NUM> may axially move along the insertion axis A toward and away from the shaft engagement socket <NUM>. The distance that the retainer <NUM> may move may be limited by the size of the channel <NUM> and the head <NUM> of the attachment clip <NUM>. When the head <NUM> is in contact with the floor <NUM> of the channel <NUM>, the retainer <NUM> may be at its maximum distance from the shaft engagement socket <NUM>, and when the head <NUM> is in contact with the ceiling <NUM>, the retainer <NUM> may be at its minimum distance from the shaft engagement socket <NUM>. It will also be understood that the retainer <NUM> may be positioned between the maximum and minimum distances.

Those of ordinary skill in the art will recognize that the attachment clip is not intended to be a limitation, nor is it the singular means of attachment.

The amount of force required to move the retainer <NUM> from the locking position to the unlocking position may be varied depending on the desired applications. To allow the shaft <NUM> to be removed from the retention assembly <NUM>, the finger <NUM> should be deflected such that it does not contact the shaft <NUM>. Preferably, the finger <NUM> should be deflected to move the protrusion <NUM> out of the notch <NUM>. To remove the finger <NUM> from the shaft, the finger <NUM> can be deflected by a minimal deflection distance. The greater the minimal deflection distance, the more force will be required to deflect the finger <NUM> to remove it from contacting the shaft <NUM>. To reduce the required force of moving the retainer from the locking position to the unlocking position, the minimal deflection distance can be reduced. The minimal deflection distance may decreased by various methods, and this disclosure is not limited by any particular method. Suitable methods include decreasing the thickness of the finger <NUM>, forming the finger <NUM> out of a more malleable material, reducingthe size of the protrusion <NUM>, and disposing the finger <NUM> radially farther away from the insertion axis A. Conversely, to increase the force required to move the finger <NUM> the minimal deflection distance, the finger <NUM> may be thicker, may include a more rigid material, and may be positioned closer to the insertion axis A.

In some aspects, for example as shown in <FIG>, the body <NUM> of the retainer <NUM> may be a solid and rigid component. In other aspects, the body <NUM> may be configured to deflect when the finger <NUM> deflects. As seen in <FIG> and <FIG>, the body <NUM> may define one or more cutouts <NUM>. The cutouts <NUM> may be cavities that extend through the body <NUM>, or they may be indentations in the body <NUM> that do not extend all the way through the body <NUM>. The cutouts <NUM> allow the body <NUM> to operate as a spring and deform radially away from the insertion axis A when the finger <NUM> is deflected in the same direction. The amount of deformation may be varied. For example, to increase deformation, more cutouts <NUM> may be present between the opening <NUM> and the outer wall <NUM>, the cutouts <NUM> may be larger (thus reducing the size of the body <NUM>), or the cutouts <NUM> may be positioned to reduce the amount of force required to deform the body <NUM>. Conversely, to decrease deformability of the body <NUM>, fewer or no cutouts <NUM> may be present, the cutouts <NUM> may be smaller, or the cutouts <NUM> may be disposed to increase rigidity of the body <NUM>.

Referring to <FIG> and <FIG>, the retainer <NUM> may include four fingers <NUM> and a plurality of cutouts <NUM>. The cutouts <NUM> may be disposed directly orthogonal to each finger <NUM> and be linearly between each finger <NUM> and the outer wall <NUM>. The cutouts <NUM> may be offset such that they are orthogonal to the space shown between each finger <NUM> and are between that space and the outer wall <NUM>. In some aspects, some cutouts <NUM> may be positioned orthogonal to the finger <NUM>, while other cutouts <NUM> may be positioned orthogonal to the space between adjacent fingers <NUM>.

The cutouts <NUM> may be round, oblong, rectangular, arcuate, S-shaped, zigzag, or another suitable shape, and this disclosure is not limited to any particular dimension of the cutouts <NUM>. The retainer <NUM> may include one or more cutouts <NUM> of the same shapesand dimensions, or the retainer <NUM> may include cutouts <NUM> having different shapes and dimensions.

Although <FIG> depicts a solid body <NUM> and three fingers <NUM> while <FIG> depicts a body <NUM> having cutouts <NUM> and four fingers <NUM>, it will be understood that the arrangements are interchangeable and are not limited to the exemplified drawings. For example, a retainer <NUM> having a solid body <NUM> may have four fingers <NUM>, and a retainer <NUM> having a body <NUM> with cutouts <NUM> may have three fingers <NUM>. Other combinations of components and number of fingers <NUM> may exist as well, and the disclosure is not limited to only the exemplified drawings.

In some aspects, it may be advantageous to ensure that the shaft <NUM> is moved into the retention assembly <NUM> at a specific angle and orientation. If the shaft <NUM> is inserted into the opening <NUM> at an improper angle, the retainer <NUM> may be damaged. For example, one or more fingers <NUM> may be deformed or broken. In some aspects, the shaft <NUM> may not be engaged with the shaft engagement socket <NUM> properly, leading to poor connection to the base <NUM> and to inadequate use of the connected tool.

To improve the engagement of the shaft <NUM> with the retention assembly <NUM>, one or more guides <NUM> may be disposed on the retainer <NUM>. When the shaft <NUM> is moved into the opening <NUM>, the proximal end <NUM> of the shaft <NUM> contacts the one or more guides <NUM>. As the shaft <NUM> moves through the opening <NUM>, the shaft <NUM> is oriented to the desired angle relative to the insertion axis A. In some aspects, the proximal end <NUM> of the shaft <NUM> may include a keyed portion <NUM> configured to complement the guides <NUM>, such that the shaft <NUM> is permitted to pass through the guides <NUM> and enter the opening <NUM> only when the shaft <NUM> is in the desired orientation. Conversely, if the shaft <NUM> is not oriented in the desiredorientation such that the keyed portion <NUM> corresponds to the guides <NUM>, then the shaft <NUM> may not be permitted from passing into the retainer <NUM>. The keyed portion <NUM> may be defined by the one or more locking surfaces <NUM> at the socketing region <NUM>. The guides <NUM> may be gaps between adjacent fingers <NUM>, for example, as shown in <FIG>. In such aspects,the keyed portion <NUM> may be dimensioned to correspond to the gaps such that the shaft <NUM> can be inserted into the retainer <NUM> only when the keyed portion <NUM> aligns with the gaps.

Although the guides <NUM> are depicted in <FIG> showing a retainer <NUM> having four fingers <NUM>, it will be understood that the guides <NUM> as described above can be used with retainers having one, two, three, or any other suitable number of fingers <NUM>. For example, the retainer <NUM> depicted in <FIG> that has three fingers <NUM> may include one or more guides <NUM> as described.

An exemplary method <NUM> of engaging a shaft <NUM> with the retention assembly <NUM> is depicted in the flowchart of <FIG>. First, as shown in step <NUM>, the shaft 14is aligned with the opening <NUM> of the retainer <NUM>. The alignment step may include orienting the shaft <NUM> such that the keyed portion <NUM>, if present, engages with the guide <NUM>. This is exemplified in <FIG>. Then, in step <NUM>, the shaft <NUM> is moved axially along insertion axis A towards the shaft engagement socket <NUM>. The shaft <NUM> contacts the finger <NUM>, for example, at the protrusion <NUM>. This is shown in <FIG>.

An alternative connection between the shaft engagement socket <NUM> and the retainer <NUM> is presented in <FIG> and <FIG>. This alternative illustrates a means to attach the retainer <NUM> to the shaft engagement socket <NUM> via the first interface <NUM> and the second interface <NUM>. The interfaces form a connection. The connection may be a fixation means. A non-exclusive list includes latches and catches, friction, threaded, sonic weld, adhesive, glue, and the like. The fixation means functions to fix the shaft engagement socket <NUM> and the retainer <NUM> together either temporarily or permanently depending on the intended use.

As the shaft <NUM> continues to be moved along the insertion axis A, the shaft <NUM> forces the fingers <NUM> to radially deflect away from the shaft <NUM> and the insertion axis A in step <NUM> and as shown in <FIG>. The shaft <NUM> is then moved past the fingers <NUM> and the protrusions <NUM> such that the notch <NUM> contacts the fingers <NUM>, preferably at the protrusion <NUM>. In step <NUM>, the protrusions <NUM> engage with the notch <NUM>. At this point, the socketing region <NUM> is in the shaft receptacle <NUM> and engaged with the shaft engagement socket <NUM>, and the shaft <NUM> is secured to the retention assembly <NUM>. This is depicted in <FIG>. In an optional step <NUM>, to remove the shaft <NUM> from the retention assembly <NUM>, the retainer <NUM> may be moved axially towards the shaft engagement socket <NUM> until the fingers <NUM> contact the shaft engagement socket <NUM> at the ramp <NUM>. As shown in <FIG>, the sliding surface <NUM> of the finger <NUM> slides along the ramp <NUM> toward the proximal end 116a of the ramp <NUM>. This sliding forces the fingers <NUM> to deflect radially away from the shaft <NUM> such that the fingers <NUM> do not contact the notch <NUM> and the protrusions <NUM> are moved out of the notch <NUM>. After this, in an optional step <NUM>, the shaft <NUM> may be removed axially along the insertion axis A away from the shaft engagement socket <NUM> and removed from the retentionassembly <NUM> altogether.

The retainer <NUM> may include different materials. Alternatively, the retainer <NUM> may be a unitary integrated piece comprised of a uniform material. Materials may include metals, plastics, and resins. In some aspects, the retainer <NUM> may include polypropylene, polytetrafluoroethylene (PTFE), polyethylene, or another suitable plastic. It will be appreciated that in aspects of this disclosure used in the medical field, the plastic needs to be suitable for medical use.

The retainer <NUM> may be designed and intended to be disposable after a limited number of uses. In some aspects, the retainer <NUM> may be designed to be disposed after a single use. The disposability is advantageous because it allows the retainer <NUM> to be manufactured out of cheaper materials. In aspects where the retainer <NUM> is intended to be disposable, the retainer <NUM> is formed of materials that are not designed for heat sterilization that would otherwise be necessary to reuse medical devices. In such aspects, instead of sterilizing the retainer <NUM> and reusing it, the retainer <NUM> is disposed of and a new retainer <NUM> is implemented.

Claim 1:
A retention assembly (<NUM>) for connecting a base to a tool having a shaft (<NUM>), wherein the retention assembly (<NUM>) comprises:
a shaft engagement socket (<NUM>) defining a shaft receptacle (<NUM>) configured to receive the shaft along an insertion axis;
a retainer (<NUM>) configured to releasably secure the shaft (<NUM>) to the shaft engagement socket (<NUM>), the retainer (<NUM>) having a body (<NUM>) that defines an opening extending therethrough, the opening being dimensioned to receive the shaft; and
at least one finger (<NUM>) extending from the body (<NUM>) of the retainer (<NUM>), the at least one finger (<NUM>) defining a sliding surface and being configured to contact the shaft,
characterized in that
the sliding surface of the at least one finger (<NUM>) is configured to slidably contact a ramp on the shaft engagement socket;
wherein the retainer (<NUM>) is configured to translate relative to the shaft engagement socket (<NUM>)along the insertion axis, such that when the retainer (<NUM>) is translated toward the shaft engagement socket, the sliding surface of the at least one finger (<NUM>) slides along the ramp of the shaft engagement socket and causes the at least one finger (<NUM>) to move away from the shaft (<NUM>), and when the retainer (<NUM>) is translated away from the shaft engagement socket (<NUM>), the sliding surface of the at least one finger (<NUM>) slides along the ramp and causes the at least one finger (<NUM>) to move towards the shaft (<NUM>).