LOCKING ARTICULATED ARTIFICIAL FINGER ASSEMBLY

An artificial finger assembly includes a residual finger socket adapted to receive a residual finger of the wearer, and a hinge arranged rearwardly of the residual finger socket. The assembly further includes a pair of controlling arms pivotally coupled to the hinge and including a first controlling arm and a second controlling arm coupled to the residual finger socket. A middle finger portion extends forwardly of the socket and is configured to pivot relative to the residual finger socket. The first controlling arm is pivotally coupled to the middle finger portion. A fingertip portion is pivotally coupled to the middle finger portion. A lock assembly is configured to lock the pair of controlling arms together to prevent the pivoting of the controlling arms, the middle finger portion, and the fingertip portion.

TECHNICAL FIELD

The present disclosure relates, generally, to an artificial finger assembly. More particularly, the present disclosure pertains to an artificial finger assembly allowing an amputee to lock the assembly in addition to regaining control of the flexion and extension movements of an artificial finger.

BACKGROUND INFORMATION

Presently the inner construction of an artificial finger is composed of a sponge-like filling. Occasionally, artificial fingers are created with fixable joints as used in action-figure leg joints. These joints provide for stationary positioning of the finger. Presently, technology with smart materials keeps many waiting for a new wave of prosthetic advancements. The problems faced with creating electronic artificial fingers for finger amputees are size and cost. Unfortunately, cost will prevent many in need from obtaining expensive electronic prostheses. Creating self-contained electronic finger prostheses offers additional difficulties due to the limited space provided. Attempts have been made to solve the problem of replacing a missing finger with a mechanical device that was more appropriately designed for a robot than a human.

SUMMARY OF DISCLOSURE

One aspect of this disclosure relates to an artificial finger assembly adapted to be engaged with a residual finger of a wearer and configured to mimic flexion and extension of a finger. The artificial finger assembly includes a residual finger socket adapted to receive the residual finger of the wearer and adapted to engage with the residual finger. The finger assembly also includes a hinge arranged rearwardly of the residual finger socket, and a pair of controlling arms pivotally coupled to the hinge and including a first controlling arm and a second controlling arm coupled to the residual finger socket. The finger assembly further includes a middle finger portion extending forwardly of the residual finger socket and configured to pivot relative to the residual finger socket. The first controlling arm is pivotally coupled to the middle finger portion. Moreover, the finger assembly includes a fingertip portion arranged forwardly of the middle finger portion and pivotally coupled to the middle finger portion. Furthermore, the finger assembly includes a lock assembly configured to lock the pair of controlling arms together to prevent the pivoting of the controlling arms, the middle finger portion, and the fingertip portion in response to a downward force exerted by the residual finger on the residual finger socket when the fingertip portion is in contact with an object.

In some additional, alternative, or selectively cumulative embodiments, the hinge is a track hinge having an arcuate track and the second controlling arm is configured to slide along the arcuate track.

In some additional, alternative, or selectively cumulative embodiments, the first controlling arm is pivotally coupled to the hinge and the middle finger portion.

In some additional, alternative, or selectively cumulative embodiments, the residual finger socket includes a movable floor, and the lock assembly includes at least one locking gear coupled to the middle finger portion and the first controlling arm and including a plurality of teeth. The lock assembly also includes at least one locking arm pivotally coupled to the residual finger socket and including a hook. The hook engages with the plurality of teeth in response to pivoting of at least one locking arm due to the downward force applied on the movable floor when the fingertip portion is arranged contacting the object.

In some additional, alternative, or selectively cumulative embodiments, the fingertip portion includes a pair of fingertip cores pivotally coupled to the middle finger portion and defining a gap therebetween, a retractable pulley slidably arranged inside the gap and defining a channel, a spring arranged inside the channel, a spring controlling lever pivotally coupled to the pair of fingertip cores and arranged inside the channel and above the spring, and a toggle switch engaged with the spring controlling lever and configured to be displaced in a lateral direction to move the spring controlling lever between the first position and the second position. In the first position, the spring controlling lever is arranged inside a cutout of the retractable pulley to prevent sliding of the retractable pulley. In the second position, the spring controlling lever is arranged outside the cutout facilitating a compression of the spring in response to sliding of the retractable pulley due to the pivoting of the fingertip portion in a rearward direction when the fingertip portion abuts the object.

In some additional, alternative, or selectively cumulative embodiments, the residual finger socket is a ring. The lock assembly includes a block coupled to the second controlling arm and arranged above the ring, a pair of vertically extending pillars arranged spaced apart from each other, wherein lower ends of the pillars fixedly coupled to the ring, wherein the pillars extend inside the block and configured to slide in a vertical direction inside the block, a pair of spring arranged surrounding the pair of pillars and biasing the pillars to an upward position. The upper ends of the pillars are arranged contacting the pair of blocks in the upward position. The lock assembly also includes a first lever extending inside the block in a lateral direction and pivotally coupled to a bolt slidably coupling one of the pair of pillars to the block. The first lever pivots in response to the sliding of the associated pillar in the vertical direction relative to the block. The lock assembly further includes a second lever pivotally coupled to the first lever and extending in the lateral direction and configured to be removably engaged with the first controlling arm to lock the first and second controlling arms.

In some additional, alternative, or selectively cumulative embodiments, the second lever includes a protrusion and the first controlling arm includes at least one groove. The protrusion extends inside the groove in response to a downward movement of the pillar relative to the block when the ring is depressed downwardly upon engagement of the fingertip portion with the object.

In some additional, alternative, or selectively cumulative embodiments, the second lever moves towards the first controlling arm when the ring is depressed downwardly.

In some additional, alternative, or selectively cumulative embodiments, the second lever is disengaged from the first controlling arm upon removal of the downward force on the ring as the pillar moves upwardly due to a force applied by the springs.

Additional aspects and advantages will be apparent from the following detailed description of example embodiments, which proceeds with reference to the accompanying drawings.

DETAILED DESCRIPTION

Example embodiments are described below with reference to the accompanying drawings. Unless otherwise expressly stated in the drawings, the sizes, positions, etc., of components, features, elements, etc., as well as any distances therebetween, are not necessarily to scale, and may be disproportionate and/or exaggerated for clarity.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be recognized that the terms “comprise,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range, as well as any sub-ranges therebetween. Unless indicated otherwise, terms such as “first,” “second,” etc., are only used to distinguish one element from another. For example, one element could be termed a “first element” and similarly, another element could be termed a “second element,” or vice versa. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Unless indicated otherwise, the terms “about,” “thereabout,” “substantially,” etc. mean that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.

Spatially relative terms, such as “right,” left,” “below,” “beneath,” “lower,” “above,” and “upper,” and the like, may be used herein for ease of description to describe one element's or feature's relationship to another element or feature, as illustrated in the drawings. It should be recognized that the spatially relative terms are intended to encompass different orientations in addition to the orientation depicted in the figures. For example, if an object in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can, for example, encompass both an orientation of above and below. An object may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

Unless clearly indicated otherwise, all connections and all operative connections may be direct or indirect. Similarly, unless clearly indicated otherwise, all connections and all operative connections may be rigid or non-rigid.

Like numbers refer to like elements throughout. Thus, the same or similar numbers may be described with reference to other drawings even if they are neither mentioned nor described in the corresponding drawing. Also, even elements that are not denoted by reference numbers may be described with reference to other drawings.

Many different forms and embodiments are possible without deviating from the spirit and teachings of this disclosure and so this disclosure should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the disclosure to those skilled in the art.

Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Referring toFIGS.1to7, an artificial finger assembly100, also referred to as a finger prosthesis100, is shown, according to an example embodiment of the disclosure. The prosthesis100includes a series of reciprocally and transversely interconnected components that form the shape and replace the missing portion of an amputated finger. The movement of the artificial finger segments are controlled by the remaining portion of an amputated finger, also referred to as residual finger, when present, or an adjacent finger when a finger is completely missing using leverage.

As shown, the prosthesis100includes a hand stabilization bracket102adapted to be positioned on a palm of a wearer and a pair of bands104removably engaged with the hand stabilization bracket102and adapted to be fastened to the palm of the wearer. The bands104and the hand stabilization bracket102together provide a secure means of fastening each artificial finger desired by the user. The prosthesis100also includes a track hinge stabilization bracket108and a finger connection bracket110arranged between the track hinge stabilization bracket108and the hand stabilization bracket102and connecting the track hinge stabilization bracket108to the hand stabilization bracket102.

Further, the prosthesis100includes a track hinge112having a first end connected to the hinge stabilization bracket108and a second end arranged distally from the hinge stabilization bracket112. The track hinge112includes an arcuate channel114or groove i.e., track114extending between the first end and the second end in a longitudinal direction. Additionally, the prosthesis100includes a pair of controlling arms, for example, an upper controlling arm116(i.e., first controlling arm116) and a lower controlling arm118(i.e., a second controlling arm118), engaged to the track hinge112and configured to control the pivoting of various components of the prosthesis100to enable flexion and extension of the artificial finger assembly. A first end of the upper controlling arm116is pivotally engaged to the second end of the track hinge112using a single screw and is able to pivot between an extended position and a downward position without conflicting with the lower controlling arm118.

As shown, the lower controlling arm118includes a curved shape and is slidably coupled with the tack hinge112and configured to slide along the track114and follow a path defined by the track114. To enable the slidable engagement of the lower controlling arm118with the track hinge112, the prosthesis100includes a pair of slidable track guides120,122that are arranged on either side of the lower controlling arm118and hold the lower controlling arm118in position and prevents a lateral movement of the lower controlling arm118relative to the track hinge112. As shown, the track guides120,122are arranged/disposed at a first end of the lower controlling arm118. The controlled movement of the lower controlling arm118along the curvature of the track114forces the lower controlling arm118to pivot in a manner that mimics the movement of a pivot point which is arranged at the center of the oval arc located beneath the track hinge112. The movement of the curved lower controlling arm118mimics a pivot point of the user's metacarpal joint allowing an external mechanical device to follow the same bending pattern as the users controlling residual finger.

A second end of the lower controlling arm118is connected to a residual finger socket124of the prosthesis using two screws and nuts. The residual finger socket124is configured to receive the residual finger of the wearer and is engaged with the residual finger of the wearer. As shown, the residual finger socket124includes a first end to which the second end of the lower controlling arm118is attached, and a second end arranged distally to the lower controlling arm118. Moreover, the socket124includes a moveable floor126that can be pressed down by the users' residual finger once the prosthesis100is pressed against an object allowing pressure to be exerted on it.

Further, the prosthesis includes at least one locking arm128, for example, a pair of locking arms128, coupled to the socket124and extending along a length of the socket124. Each of the locking arms128includes a first end having an eye portion132and a second end having a hook134. The eye portions132of the locking arms128are arranged inside a fork portion of the residual finger socket124located underneath the floor126of the residual finger socket124and are connected to the fork portion of the socket124. The second ends of the locking arms128extend outwardly of the second end of the socket124in the longitudinal direction. Moreover, the prosthesis100includes a slide bracket136having an eye portion138and a curved bracket portion140extending in a longitudinal direction from the eye portion138. The eye portion138is arranged at the first end of the socket124and inside the fork portion of the socket124. The eye portion138of the slide bracket136and the eye portions132of the locking arms128are arranged inside the fork portion of the socket124such that the eye portions132of the locking arms128are arranged on opposite side of the eye portion138of the slide bracket136and the eye portions132of the locking arms128are arranged between the eye portion138of the slide bracket136and the forks of the fork portion of the socket124. The socket124, the locking arms128and the slide bracket136are coupled to each other via a single screw. Further, the curved bracket portion140of the slide bracket136is engaged with the second end of the socket124via a screw that extends in the longitudinal direction. As shown, a portion of the curved bracket portion140is arranged outwardly of the second end of socket124in the longitudinal direction.

Moreover, the prosthesis100includes a middle finger portion142having a sliding stabilizer144configured with the slide bracket136and includes a vertical extending channel from a bottom end to a top end, and the curved bracket portion140of the slide bracket136extends through the vertical channel. As can be seen, a free end of the curved bracket portion140extends outwardly of the top end of the sliding stabilizer144and is attached to the second end of the socket124via the screw. The sliding stabilizer144includes an inverted L shape such that a horizontal arm146extends outwardly in the longitudinal direction from the vertical channel. The sliding stabilizer144is arranged to slide up and down the slide bracket136, simulating a pivot point at the center of the oval formed by both components when connected.

Additionally, prosthesis100includes at least one locking gear, for example, a pair of locking gears150, arranged outwardly and on opposite sides of the sliding stabilizer144and coupled to the sliding stabilizer144. Each of the locking gears150includes a substantially inverted L shape having a first portion154extending horizontally and in the longitudinal direction and a second portion156extending vertically downwardly of the first portion154. In an assembly of the locking gears150, the first portion154of each of the locking gears150extends along the horizontal arm146of the sliding stabilizer144and is connected to the horizontal arm146via two screws. Moreover, the second portions156of the locking gears150extend along a vertical arm148of the sliding stabilizer144. Further, each of the locking gears150includes a plurality of teeth160extending rearwardly of the vertical arm148and are adapted to removably engage with the hooks134of the locking arms128to lock the relative pivoting of the various portions of the prosthesis100. The locking arms128and the locking gears150together define a lock assembly162of the prosthesis100.

To cover the sliding stabilizer144and the locking gears150, the prosthesis100includes a lock shroud164having a horizontally oriented U shape and defining a cavity to receive the sliding stabilizer144and the locking gears150. The lock shroud164includes an upper horizontally oriented arm portion166, a lower horizontally oriented arm portion168arranged below and at a distance from the upper arm portion166, and a vertically extending column portion170extending between the upper arm portion166and the lower arm portion168. In the assembly of the locking gears150and the sliding stabilizer144with the lock shroud164, the first portions154of the locking gears150and the horizontal arm146of the sliding stabilizer144are arranged inside the upper arm portion166, while the second portions156of the locking gears150and the vertical arm148of the sliding stabilizer144are arranged inside the column portion170. The upper arm portion166, the first portions154of the locking gears150and the horizontal arm146are connected to each other via two screws. Further, the first portions154of the locking gears150extend forwardly of the horizontal arm146of the sliding stabilizer144in the longitudinal direction is coupled with an end of the upper arm portion166via single screw.

Further, the prosthesis100includes a lever172coupled to the shroud164, the locking gears150, and the upper controlling arm116. As shown, the lever172includes a body174and a fork structure176extending rearwardly of the body174. Fork structure176includes three fork arms, for example, a first fork arm, a second fork arm, and a third fork arm arranged spaced apart from each other and defining two cavities between them. For example, a first cavity is defined between the first fork arm and the second form arm, while a second cavity is defined between the second fork arm and the third fork arm. As shown, the first fork arm and the second fork arm extend inside the lower arm portion168of the shroud164and is coupled with the lower arm portion168via screws. Also, the second portion156of the one of the locking gears150is arranged between the first fork and the lower arm portion168and are coupled to each other via a first screw. Moreover, in the engagement of the lever172with the shroud164, the third fork arm is arranged outside the shroud172such that a wall of the lower arm portion168of the shroud164and the other of the locking gears150is arranged between the third fork and the second fork. Further, the upper controlling arm116is connected to the third fork, the second fork, the locking gear150, and the wall of the lower arm portion168via a second screw. The upper controlling arm116is connected with the shroud164and the lever172such that the third fork is arranged between the upper controlling arm116and a wall of the lower arm portion168in a lateral direction.

Additionally, the lever172is engaged to the shroud164such that the body174is arranged between the upper arm portion166and the lower arm portion168and extends forwardly and upwardly relative to the fork structure176. The body174is coupled to the upper controlling arm116and a fingertip pulley180of the prosthesis100arranged inside a keyway of the body174via another screw. The fingertip pulley180is arranged proximate to the first fork in the lateral direction and extends outwardly and forwardly in the longitudinal direction from the shroud164.

Furthermore, the prosthesis100includes a fingertip portion181having a first fingertip core182, a second fingertip core184, and a retractable pully186arranged between the first fingertip core182and the second fingertip core184. The first fingertip core182includes a first front portion188and a first rear portion190arranged offset from each other in the lateral direction. Similarly, the second fingertip core184includes a second front portion192and a second rear portion194arranged offset from each other in the lateral direction. In the assembly, the first rear portion190and the second rear portion194abuts each other and are disposed inside the upper arm portion168of the shroud164and between the front portions of the locking gears150and are engaged with each other via a screw. Accordingly, the upper arm portion168, the locking gears150, and the rear portions190,194of the fingertip cores182,184are attached to each other via a screw. Therefore, the fingertip cores182,84are pivotally coupled to the shroud172and the locking gears150.

Further, the retractable pulley186slidably extends inside a gap defined between the first front portion188of the first fingertip core182and the second front portion192of the second fingertip core184. As shown, the retractable pulley186includes a fork portion that is pivotally coupled to a front end of the fingertip pulley180, and a housing portion arranged inside the gap and defining a channel198. A spring200is arranged inside channel198and extends in the longitudinal direction. The retractable pulley186sits slidably engaged inside the fingertip cores182,184.

Moreover, the rear portions190,194of the fingertip cores182,184together define a keyway and a toggle switch202extends inside the keyway and is coupled to the fingertip cores182,184. The toggle switch202is adapted to slide between a first position and a second position in the lateral direction within the confines of the keyway. Also, the switch202includes a small nodule204that protrudes from the front of the switch202and fits inside of a groove disposed at a rear end of a spring controlling lever210. The spring controlling lever210is arranged between the front portions188,192of the fingertip cores182,184, above the spring200and is pivotably coupled with the fingertip cores182,184. As shown, the first fingertip core182includes a first bracket212arranged above the retractable pulley186, while the second fingertip core184includes a second bracket214arranged downwardly of the retractable pulley186, aligned with the first bracket212. The spring controlling lever210is pivotally coupled with the first bracket212and the second bracket214and is adapted to pivot about central axes of the brackets212,214. The spring controlling lever210is adapted to pivot to a first position and a second position in response to the displacement of the toggle switch202to the first position and the second position, respectively.

Also, the prosthesis100includes a grip cap220configured to partially house the fingertip cores182,184and is attached to the fingertip cores182,184via a screw. Moreover, the screw engaging the spring controlling lever219with the first bracket212and the second bracket214, extends through a lower wall of the grip cap220and attaches the spring controlling lever210with the grip cap220. In the first position of the toggle switch202, a tip of the spring controlling lever210is arranged inside a cutout222arranged at a forward end of the retractable pulley186, while in the second position of the toggle switch202, the tip of the spring controlling lever210is arranged outwardly of the cutout222. Accordingly, in the first position, the fingertip portion181is restricted from pivoting rearwardly relative to a middle finger portion142when the grip cap220contacts an object. In the second position, the fingertip portion181is adapted to be pivoted rearwardly relative to the middle finger portion142, enabling a movement of the retractable pulley186in a rearward direction. As the retractable pulley186moves rearwardly due to the rearward pivoting of the fingertip portion181upon a contact of the grip cap220with the object, spring200is compressed, enabling an improved grip of the prosthesis100on the object when holding the object.

The lock assembly162is configured to lock the finger assembly100and locks the pivoting of the controlling arms116,118, the middle finger portion142, and the fingertip portion181. The lock assembly162locks the finger assembly100when the hooks134of the locking arms128are in engagement with the teeth160of the locking gears150. The locking arms128are engaged with the locking gears150in response to the pivoting of the locking arms128due to a downward push force applied on the movable floor126of the socket124when the fingertip181(i.e., grip cap220) is arranged contacting an object. The lock on the pivotal movement of the controlling arms116,118, the middle finger portion142, and the fingertip portion181is removed upon removal of the push down force on the movable floor126.

Referring toFIGS.8to12, an artificial finger assembly300(i.e., prosthesis300) is shown, according to an alternative embodiment of the disclosure. The prosthesis300includes a hand stabilization bracket302adapted to be engaged to a palm of the wearer, a hinge304coupled to the hand stabilization bracket302and having a pair of forks306,308extending in a longitudinal direction and away from the hand stabilization bracket302. Further, the prosthesis300includes a pair of controlling arms, for example, an upper controlling arm310(i.e., first controlling arm310) and a lower controlling arm312(i.e., a second controlling arm312), pivotally coupled to the pair of forks306,308. As shown, the upper controlling arm310is connected to an upper fork306of the pair of forks306,308, while the lower controlling arm312is connected to a lower fork308of the pair of forks306,308. Furthermore, the prosthesis100includes a residual finger socket316, for example, a ring318, arranged forwardly of the controlling arms310,312and engaged to the lower controlling arm312. The ring318is configured to receive a residual finger of the wearer and is supported on the residual finger of the wearer. As shown, the upper controlling arm310includes a first portion320that extends between the ring318and the hinge304, and a second portion322that extends forwardly of the ring318. Similarly, the lower controlling arm312includes a first portion324that is arranged between the hinge304and the ring318and a second portion326that extends forwardly in a longitudinal direction from the ring318. As shown, the ring318and the controlling arms310,312are arranged such that the ring318is arranged beneath the controlling arms310,312.

Moreover, the prosthesis300includes a middle finger portion330pivotally connected to the controlling arms310,312, and a fingertip portion332pivotally connected to the middle finger portion330. The middle finger portion330and the fingertip portion332are configured to pivot in response to a pull-down force applied on the ring318by the wearer and hence on the controlling arms310,312by the residual finger. Also, it may be appreciated that to enable pivoting of the middle finger portion330relative to the controlling arms310,312and the fingertip portion332relative to the middle finger portion330, the middle finger portion330includes a plurality of levers arranged and engaged with one or more of the controlling arms310,312and the fingertip portion332.

Further, the prosthesis300includes a lock assembly340to lock the pivoting of middle finger portion330, the controlling arms310,312, and the fingertip portion332. As shown, the lock assembly340includes a block342, a pair of vertically extending pillars344,346, a pair of springs348,350, and a lever370. The block342includes a front block352and a rear block354attached to each other via a plurality of screws and is arranged between the controlling arms310,312and the ring318in the vertical direction. Further, the block342are attached to the lower controlling arm312. Also, the pair of pillars344,346are arranged spaced apart from each other and extends vertically upwardly from the ring318inside block342. The pair of pillars344,346are attached to ring318such that the ring318and pillars344,346moves upwardly and downwardly together. Upper ends of the pillars344,346include eye portions360,361and horizontal bolts362,364extend through the elongated sockets of the front block352, the rear block354, and the associated eye portions360,361such that the eye portions360,361are connected with the associated bolts362,364, Moreover, eye portions360,361are arranged in contact the upper end of the block342. Also, the pair of springs348,350are arranged inside the block342, surrounding the pillars344,346such that upper ends the springs348,350contact the associated eye portions360,361, while lower ends of the springs348,350contact the block342. Accordingly, as the ring318is pulled downwardly by the residual finger, the pillars344,346moves vertically downwardly relative to the block342, causing compression of the springs348,350. As the pull-down force is removed on the ring318, the springs348,350forces the pillars344,346to move upwardly.

Further, the lock assembly340includes a first lever374and a second lever370arranged inside the block342and pivotally coupled teach other. The levers374,370extend in a lateral direction between the pillars344,346. The second lever370includes a first end arranged proximate to the lower controlling arm312and pivotally coupled to a horizontally extending rod372, and a second end arranged proximate to the upper controlling arm310. Further, the second lever370includes a protrusion380arranged at the second end of the second lever370and configured to be removably engaged with the upper controlling arm310to lock the controlling arms310,312with each other and hence lock the pivoting of middle finger portion330, the fingertip portion332, and the controlling arms310,312. To facilitate the engagement of the protrusion380with the upper controlling arm310and retain the protrusion380engaged with the upper controlling arm310, the upper controlling arm310includes a tooth382that extends downwardly towards the block342from an elongated body of the upper controlling arm310, and the tooth382includes at least one groove384arranged facing the second end of the lever370to receive the protrusion380for engaging the lever370with the upper controlling arm310.

To pivot and move the second lever370towards the upper controlling arm310, the first lever374is pivotally coupled to the bolt362that extends through the eye portion362of the pillar344. As the ring318is pushed down by the residual finger, the pillars344,346moves downwardly reactive to the block342, causing a pivoting of the first lever374relative to the bolt361causing a movement of the second lever370towards the upper controlling arm310. It may be appreciated that the upper controlling arm310is configured such that the upper controlling arm310moves back slightly during articulation in relation to the lower arm312and moves forward during extension. Accordingly, when the finger assembly300is articulated by pulling down the ring318, the at least one groove384is arranged in alignment with the protrusion380, with the protrusion380disposed away from the at least one groove384. In the articulate position, when the fingertip portion contacts a surface and the ring318is depressed further, the second lever370moves towards the upper controlling arm310and the protrusion318extends inside the aligned groove374locking the finger assembly in the flexed/articulated position and prevents pivoting of the controlling arms310,312, the middle finger portion330, and the fingertip portion332.

To unlock the finger assembly, the downward force on the ring318is removed. This causes the pillars344,346to move upwardly due to force applied by the springs348,350, causing the protrusion of the second lever370to move away from the groove384, thereby disengaging the second lever374from the upper controlling arm310, and enabling the pivoting of controlling arms310,312, the middle finger portion330, and the fingertip portion332.

Many modifications and other embodiments of the disclosures set forth herein will come to mind to one skilled in the art to which these disclosures pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims.