Robotic finger structure and robot

A robotic finger structure includes a proximal phalanx; a middle phalanx rotatably connected to one end of the proximal phalanx; a distal phalanx rotatably connected to one end of the middle phalanx and defining a distal phalanx opening in a front side thereof and at one end adjacent to the middle phalanx; a connecting rod having opposite ends that are rotatably connected to the proximal phalanx and the distal phalanx, and an actuating assembly to drive the middle phalanx to rotate with respect to the proximal phalanx. The connecting rod includes a first angled segment having a first recess facing a back side of the middle phalanx. When the distal phalanx is flush with the middle phalanx, the first angled segment passes through the distal phalanx opening, and a first end of the distal phalanx opening extends into the first recess.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202010455928.4, filed May 26, 2020, which is hereby incorporated by reference herein as if set forth in its entirety.

BACKGROUND

1. Technical Field

The present disclosure generally relates to robots, and particularly to a robotic finger structure and a robot having the finger structure.

2. Description of Related Art

One conventional robot has a finger that includes a linking member rotatably connecting one phalanx to another phalanx. Since the linking member is a one-degree-of-freedom system, it is difficult for the linking member to have certain elasticity to absorb the impact and shock when the finger structure is subjected to impact.

Therefore, there is a need to provide a finger structure to overcome the above-mentioned problems.

DETAILED DESCRIPTION

Referring toFIGS.1-4, a robotic finger100includes a proximal phalanx10, a middle phalanx20, a distal phalanx30, a connecting rod40and an actuating assembly50. The middle phalanx20is rotatably connected to one end of the proximal phalanx10. The distal phalanx30is rotatably connected to one end of the middle phalanx20. A1inFIGS.4-6represents the axis of rotation between the middle phalanx20and the proximal phalanx10, and A2represents the axis of rotation between the distal phalanx30and the middle phalanx20. Referring toFIG.7, the front side10aof the proximal phalanx10, the front side20aof the middle phalanx20and the front side30aof the distal phalanx30face the same direction as the palmar side201of the palm200when the finger structure is in an extended state, which are respectively the lower side of the proximal phalanx10, the lower side of the middle phalanx20and the lower side of the distal phalanx30shown inFIGS.1and4. The back side10bof the proximal phalanx10and the back side20bof the middle phalanx20face the same direction as the dorsal side202of the palm200when the finger structure is in an extended state, which are respectively the upper side of the proximal phalanx10and the upper side of the middle phalanx20shown inFIGS.1and4.

Referring toFIGS.4,7and10-11, the front side30aof the distal phalanx30defines a distal phalanx opening31at one end adjacent to the middle phalanx20.FIG.4shows partially the distal phalanx opening31, whileFIG.9shows the complete distal phalanx opening31. The distal phalanx opening31has a first end311and a second end312that is opposite the first end311. When the finger structure100is in the extended state, the first end311is closer to the palm200than the second end312. Two opposite ends of the connecting rod40are respectively rotatably connected to the proximal phalanx10and the distal phalanx30. A3inFIGS.4to6represents the axis of rotation between the connecting rod40and the proximal phalanx10, and A4represents the axis of rotation between the connecting rod40and the distal phalanx30.

Referring toFIG.3, in one embodiment, the connecting rod40may include a first angled segment41. Referring toFIG.4, the first angled segment41defines a recess41afacing a back side20bof the middle phalanx20. One end of the first angled segment41is rotatably connected to the distal phalanx30, which allows the first angled segment41to be rotatable about the axis indicated by A4ofFIG.4. When the distal phalanx30is flush with the middle phalanx20, which is shown inFIGS.2,4, and8, the first angled segment41passes through the distal phalanx opening31, and the first end311of the distal phalanx opening31extends into the first recess41aadjacent to the bottom of the recess41a, which covers the distal phalanx opening31. Here, the distal phalanx30being flush with the middle phalanx20means that they extend in substantially the same line, or that the distal phalanx30deflect slightly from the middle phalanx20. For example, the deflection angle between the distal phalanx30and the middle phalanx20can be 5 degrees. The actuating assembly50drives the middle phalanx20to rotate with respect to the proximal phalanx10.

Compared with the conventional finger structures, in the finger structure100, the proximal phalanx10, the middle phalanx20, the distal phalanx30, and the connecting rod40constitute a four-bar mechanism. Specifically, the proximal phalanx10serves as a fixed frame, the actuating assembly50drives the middle phalanx20to swing, the distal phalanx30moves together with the connecting rod40, and the distal phalanx30swings in the same direction as the middle phalanx20. That is, when the middle phalanx20rotates in a clockwise direction, the distal phalanx30rotates in the clockwise direction; and when the middle phalanx20rotates in a counterclockwise direction, the distal phalanx30rotates in the counterclockwise direction. With such configuration, extension and flexion of the finger structure100can be realized. The finger structure ofFIG.4is in an extended state. If a straight connecting rod40′ indicated by the two-dot chain line is used, the straight connecting rod40′ will interfere with the distal phalanx30. In order to avoid interference, a larger distal phalanx opening is needed. In the finger structure as described above, the connecting rod40includes the first angled segment41having a recess41afacing a back side20bof the middle phalanx20. When the finger structure100is extended (i.e., when the distal phalanx30is flush with the middle phalanx20as shown inFIGS.2and4), the first end311of the distal phalanx opening311extends into the recess41a. In this case, no interference occurs without increasing the size of the distal phalanx opening311.

Referring toFIGS.4-6, during the flexion of the finger structure100, that is, the distal phalangeal30and the middle phalanx20gradually change from being flush each other to being perpendicular to each other, the first angled segment41will gradually enter the distal phalanx30. It can be seen that the first angled segment41has no adversely effect on the extension and flexion of the figure structure. Compared with conventional finger structures, the distal phalanx opening31of the finger structure100can be made smaller, which can improve the overall appearance integrity of the distal phalanx30. Due to the existence of the first angled segment41of the connecting rod40, when the distal phalanx shell30is subjected to impact, the connecting rod40will show certain elasticity and absorb the impact. When the external impact ceases, the distal phalanx30will return to the original state immediately due to the existence of elasticity.

Referring toFIGS.4-6, in one embodiment, the four-bar mechanism constituted by the proximal phalanx10, the middle phalanx20, the distal phalanx30and the connecting rod40is a double rocker mechanism. Specifically, the proximal phalanx10serves as a fixed frame, and the middle phalanx20and the connecting rod40are both rockers. One end of the middle phalanx20and one end of the connecting rod40are respectively rotatably connected to the proximal phalanx10, which allows the middle phalanx20and the connecting rod40to rotate about the axes of rotation A1and A3. The opposite end of the middle phalanx20and the opposite end of the connecting rod40are respectively connected to the same end of the distal phalanx30at different positions, which allows the middle phalanx20and the connecting rod40to rotate about the axes of rotation A2and A4. The actuating assembly50drives the middle phalanx20to swing, and the distal phalanx30moves together with the connecting rod40. The distal phalanx30swings in the same direction as the middle phalanx20. That is, when the middle phalanx20rotates in a clockwise direction, the distal phalanx30rotates in the clockwise direction; and when the middle phalanx20rotates in a counterclockwise direction, the distal phalanx30rotates in the counterclockwise direction. With such configuration, extension and flexion of the finger structure100can be realized. During flexion and extension of the finger structure100, the line between the two pivot points of the middle phalanx20(i.e., the connection line between axes A1and A2) and the line between the two pivot points of the connecting rod40(i.e., the connection line between axes A3and A4) cross each other. In this way, the finger structure100can be flex and extend as a whole. That is, the actuating assembly50drives the middle phalanx20to swing, and the distal phalanx30swings in the same direction as the middle phalanx20.

In an extended state, the proximal phalanx10, the middle phalanx20and the distal phalanx30are flush with one another. In a flexed state, the proximal phalanx10is perpendicular to the middle phalanx20, and the middle phalanx20is perpendicular to the distal phalanx30. During the flexion and extension of the finger structure, the proximal phalanx10, the middle phalanx20and the distal phalanx30swing in the same direction.

Referring toFIGS.3-6, in one embodiment, the connecting rod40may further include a second angled segment42. Referring toFIG.4, the second angled segment42defines a recess42afacing the front side20aof the middle phalanx20. One end of the second angled segment42is rotatably connected to the proximal phalanx10, which allows the second angled segment42to rotate about axis A3. The recess41aof the first angled segment41and the recess42aof the second angled segment42face opposite directions. With such configuration, the elasticity of the connecting rod40can be improved to absorb external impact. When the external impact ceases, the distal phalanx30will return to the original state immediately.

Referring toFIGS.4-6and9, in one embodiment, when the distal phalanx30is perpendicular to the middle phalanx20as shown inFIG.6, the first angled segment41is received in the distal phalanx30, the second angled segment42passes through the distal phalanx opening31, and the second end312of the distal phalanx opening31opposite the first end311extends into the second recess42aof the second angled segment42adjacent to the bottom of the second recess42a. The finger structure ofFIG.6is in a flexed state. If a straight connecting rod40′ indicated by the two-dot chain line is used, the straight connecting rod40′ will interfere with the distal phalanx30. In order to avoid interference, a larger distal phalanx opening is needed. In the finger structure as described above, the connecting rod40includes the second angled segment42having the recess42a. In this case, no interference occurs without increasing the size of the distal phalanx opening311. It can be seen that the second angled segment42has no adversely effect on the extension and flexion of the figure structure. Compared with conventional finger structures, the distal phalanx opening31of the finger structure100can be made smaller, which can improve the overall appearance integrity of the distal phalanx30. As shown inFIGS.10and11, when the finger structure100is in the flexed state, the second angled segment42basically obscures the distal phalanx opening31of the distal phalanx30, reducing the area where the distal phalanx opening31is observed by people, and making the distal phalanx30have a better appearance.

Referring toFIGS.2-4,8, and9, in one embodiment, a distal opening21is defined in one end of the middle phalanx20adjacent to the distal phalanx30, the second angled segment42is received in the middle phalanx20, and the second angled segment42passes through the distal opening21. With such configuration, the connecting rod40can be better protected and the second angled segment42can be avoided to be exposed to the outside of the middle phalanx20, which allows the finger structure100to have an aesthetic appearance.

Referring toFIGS.2-4and9, in one embodiment, one end of the connecting rod40adjacent to the distal phalanx30includes a first pivot shaft43, and two ends of the first pivot shaft43are rotatably connected to two opposite inner surfaces of the distal phalanx30. For example, the opposite ends of the first pivot shaft43are rotatably received in two pivot holes33of the distal phalanx30. With such configuration, the end of the connecting rod40adjacent to the distal phalanx30can be rotatably connected to the distal phalanx30. The central axis of the first pivot shaft43is the axis of rotation A4between the connecting rod40and the distal phalanx30. The two ends of the first pivot shaft43are respectively supported on the two opposite inner surfaces of the distal phalanx30through bearings431, which can reduce the friction between the first pivot shaft43and the distal phalanx30, and is conducive to the reliable connection of the connecting rod40on the distal phalanx30. The bearings431may be mounted in the pivot holes33.

Referring toFIGS.1-3and8-11, in one embodiment, the middle phalanx20includes two mounting walls22that are spaced apart from each other and define a mounting space therebetween. One end of the distal phalanx30is received in the mounting space, and rotatably connected to the mounting walls22. In this way, one end of the distal phalanx30can be reliably rotatably connected to the middle phalanx20. The proximal end of the distal phalanx30(i.e., the end with the distal phalanx opening31) is arranged adjacent to the distal opening21of the middle phalanx20, and the two mounting walls22obscure the left and right sides of the distal opening21, so that a viewer can only observe the gap of the distal opening21at the front side20aand the back side20bof the middle phalanx20(seeFIGS.4-6), reducing the area where the distal opening21is exposed to the outside.

Referring toFIGS.2,3, and9, in one embodiment, each of the two mounting walls22defines a mounting hole221, and the distal phalanx30includes two shafts32that are rotatably received in the mounting holes221. The shafts32are rotatably supported in the mounting holes221through two bearings321. The provision of the bearings321can reduce the friction between the shafts32and the mounting holes221, so that the shafts32can be reliably received in the mounting holes221, thereby enabling one end of the distal phalanx30to be reliably rotatably connected to the middle phalanx20.

Referring toFIGS.2-6, in one embodiment, the actuating assembly50includes a linear actuator51arranged in the proximal phalanx10and a transmission member52driven by the linear actuator51and has an end connected to an output shaft511of the linear actuator51. The opposite end of the transmission member52is rotatably connected to the middle phalanx20. The axis of rotation between the transmission member52and the middle phalanx20is spaced apart a distance from the axis of rotation A1between the proximal phalanx10and the middle phalanx20. The linear actuator51may be an electric cylinder, which is convenient for outputting a predetermined displacement to control the motion of the finger structure100. The linear actuator51pushes the transmission member52to move back and forth, which can drive the middle phalanx20to rotate relative to the proximal phalanx10. It should be noted that the actuating assembly50is not limited can also adopt other means that can drive the middle phalanx20to rotate relative to the proximal phalanx10.

Referring toFIGS.2-4, in one embodiment, the transmission member52includes a connecting member521connected to the output shaft511of the linear actuator51. The connecting member521includes a guide post5211, and the proximal phalanx10defines a linear guide groove11in an inner surface thereof. The linear guide groove11extends along a direction in parallel with the output shaft511of the linear actuator51, and the guide post5211is inserted into the linear guide groove11and slidable in the linear guide groove11. The engagement of the guide post5211with the linear guide groove11can facilitate the forward and backward movement of the transmission rod52in a predetermined direction.

Referring toFIGS.2-4and9, in one embodiment, one end of the transmission member52adjacent to the middle phalanx20includes a connecting shaft524. Opposite ends of the connecting shaft524are rotatably connected to two opposite inner surfaces of the middle phalanx20. For example, the opposite ends of the connecting shaft524are rotatably received in pivot holes27of the middle phalanx20. This arrangement facilitates stable connection of one end of the transmission member52to the middle phalanx20. The central axis of the connecting shaft524is the axis of rotation between the transmission member52and the middle phalanx20. Opposite ends of the connecting shaft524are rotatably supported in the opposite inner surfaces of the middle phalanx20through two bearings5241, which can reduce the friction between the connecting shaft524and the middle phalanx20, so that the transmission member52can be reliably rotatably connected to the middle phalanx20. The bearings5241may be mounted in the pivot holes27.

Referring toFIGS.2-4,7-9, and12-13, in one embodiment, the front side20aof the middle phalanx20defines a proximal opening24at one end adjacent to the proximal phalanx10.FIG.4shows partially the proximal opening24, whileFIG.9shows the complete proximal opening24. The proximal opening24has a first end241and a second end242opposite the first end241. When the finger structure100is in an extended state, the first end241is closer to the palm200than the second end242. The transmission member52includes a first angled segment522having a first recess522athat faces a back side10bof the proximal phalanx10. The first angled segment522has an end rotatably connected to the middle phalanx20. When the proximal phalanx10, the middle phalanx20and the distal phalanx30are flush with one another as shown inFIG.4, the first angled segment522passes through the proximal opening24, and the first end241of the proximal opening24extends into the first recess522aadjacent to the bottom of the first recess522a, which covers the proximal opening24. The finger structure ofFIG.4is in an extended state. If a straight connecting rod52′ indicated by the two-dot chain line is used, the straight connecting rod52′ will interfere with the middle phalanx20. In order to avoid interference, a larger distal phalanx opening is needed. In the finger structure as described above, the transmission member52includes the first angled segment522having the recess522a. In this case, no interference occurs without increasing the size of the proximal opening24.

During the flexion of the finger structure100as shown inFIGS.5and6, that is, the middle phalangeal20and the proximal phalanx10gradually change from being flush each other to being perpendicular to each other, the first angled segment522will gradually enter the middle phalanx20. It can be seen that the first angled segment522has no adversely effect on the extension and flexion of the figure structure. Compared with conventional finger structures, the proximal opening31of the finger structure100can be made smaller, which can improve the overall appearance integrity of the middle phalanx20. Due to the existence of the first angled segment522of the transmission member40, when the distal phalanx shell30or the middle phalanx20is subjected to impact, the transmission member52will show certain elasticity and absorb the impact. When the external impact ceases, the middle phalanx20will return to the original state immediately due to the existence of elasticity.

Referring toFIGS.2-4, in one embodiment, the transmission member52includes a second angled segment523connected to an end of the first angled segment522. The second angled segment523defines a second recess523afacing a front side10aof the proximal phalanx10and has an end rotatably connected to the output shaft211of the linear actuator51. The recess522aof the first angled segment522and the recess523aof the second angled segment523face opposite directions. With such configuration, the elasticity of the transmission member52can be improved to absorb external impact. When the external impact ceases, the middle phalanx20will return to the original state immediately.

Referring toFIGS.3-6, in one embodiment, when the proximal phalanx10is perpendicular to the middle phalanx20as shown inFIG.6, the first angled segment522is received in the middle phalanx20, the second angled segment523passes through the proximal opening24, and the second end242of the proximal opening24opposite the first end241extends into the second recess523aof the second angled segment523adjacent to the bottom of the second recess523a. The finger structure ofFIG.6is in a flexed state. If a straight connecting rod52′ indicated by the two-dot chain line is used, the straight connecting rod52′ will interfere with the middle phalanx20. In order to avoid interference, a larger proximal opening is needed. In the finger structure as described above, the transmission member52includes the second angled52342having the recess523a. In this case, no interference occurs without increasing the size of the proximal opening24. It can be seen that the second angled segment523has no adversely effect on the extension and flexion of the figure structure. Compared with conventional finger structures, the proximal opening24of the finger structure100can be made smaller, which can improve the overall appearance integrity of the distal phalanx30. As shown inFIGS.12-13, when the finger structure100is in the flexed state, the second angled segment523basically obscures the proximal opening24of the middle phalanx20, reducing the area where the proximal opening24is observed by people, and making the middle phalanx20have a better appearance.

Referring toFIGS.2-4, in one embodiment, a proximal phalanx opening12is defined in one end of the proximal phalanx10adjacent to the middle phalanx20, the second angled segment523is received in the proximal phalanx10, and the second angled segment523passes through the proximal phalanx opening12. With such configuration, the transmission member52can be better protected and the second angled segment523can be avoided to be exposed to the outside of the proximal phalanx10, which allows the finger structure100to have an aesthetic appearance.

Referring toFIGS.1-4and8-13, in one embodiment, the proximal phalanx10includes two mounting walls13that are spaced apart from each other and define a mounting space14therebetween. One end of the middle phalanx20is received in the mounting space14, and rotatably connected to the mounting walls13. In this way, one end of the middle phalanx20can be reliably rotatably connected to the proximal phalanx10. The proximal end of the middle phalanx20(i.e., the end with the proximal opening24) is arranged adjacent to the proximal phalanx opening12of the proximal phalanx10, and the two mounting walls13obscure the left and right sides of the proximal opening24, so that a viewer can only observe the gap of the proximal opening24at the front side10aand the back side10bof the proximal phalanx10(seeFIGS.4-6), reducing the area where the proximal phalanx opening12is exposed to the outside.

Referring toFIGS.2-3and9, in one embodiment, each of the two mounting walls13defines a mounting hole131, and the middle phalanx20includes two shafts25that are rotatably received in the mounting holes131. The shafts25are rotatably supported in the mounting holes131through two bearings251. The provision of the bearings251can reduce the friction between the shafts25and the mounting holes131, so that the shafts25can be reliably received in the mounting holes131, thereby enabling one end of the middle phalanx20to be reliably rotatably connected to the proximal phalanx10. The bearings251can be mounted in the mounting holes131.

Referring toFIGS.2-4, in one embodiment, the middle phalanx20defines an arc-shaped guide groove26that is centered on an axis of rotation of the middle phalanx20relative to the proximal phalanx10. One end of the connecting rod40has a shaft44that passes through the arc-shaped guide groove26, and the shaft44is rotatably connected to at least one of the two mounting walls13. For example, one end of the shaft44can be rotatably received in a pivot hole132of one mounting wall13. The central axis of the shaft44is the axis of rotation between the connecting rod40and the proximal phalanx10. The shaft44passes through the middle phalanx20and is connected to the proximal phalanx10, and then one end of the connecting rod40is rotatably connected to the proximal phalanx10. Opposite ends of the shaft44are rotatably supported in the mounting walls13through two bearings441, which can reduce the friction between the shaft44and the mounting walls13, so that the connecting rod40can be reliably rotatably connected to the mounting walls13. The bearings441may be mounted in the pivot holes132.

Referring toFIGS.1-2and8-9, in one embodiment, the proximal phalanx10includes two casings19that are connected to each other and receive the actuating assembly50therein. The two casings19can be connected to each other by fasteners. With such configuration, the actuating assembly50and the transmission member52can be better protected and can be avoided to be exposed to the outside of the proximal phalanx10, which allows the finger structure100to have an aesthetic appearance. Each of the casings19defines a recess, and the two recesses form the proximal phalanx opening12after the two casings19are connected to each other.

Referring toFIGS.1-2and8-9, in one embodiment, the middle phalanx20two casings29that are connected to each other and partly receive the connecting rod40therein. The two casings29can be connected to each other by fasteners. With such configuration, the connecting rod40can be better protected and can be avoided to be exposed to the outside of the middle phalanx20, which allows the finger structure100to have an aesthetic appearance. Each of the casings29defines a recess, and the two recesses form the proximal opening21after the two casings29are connected to each other.

Referring toFIGS.1-2and8-9, in one embodiment, the distal phalanx30includes two casings39that are connected to each other and partly receive the connecting rod40therein. The two casings39can be connected to each other by fasteners. With such configuration, the connecting rod40can be better protected and can be avoided to be exposed to the outside of the distal phalanx30, which allows the finger structure100to have an aesthetic appearance. Each of the casings39defines a recess, and the two recesses form the distal phalanx opening31after the two casings39are connected to each other.

In one embodiment, a robot includes the finger structure described above.

The embodiments above are only illustrative for the technical solutions of the present disclosure, rather than limiting the present disclosure. Although the present disclosure is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that they still can modify the technical solutions described in the foregoing various embodiments, or make equivalent substitutions on partial technical features; however, these modifications or substitutions do not make the nature of the corresponding technical solution depart from the spirit and scope of technical solutions of various embodiments of the present disclosure, and all should be included within the protection scope of the present disclosure.