Patent Description:
The medical microsurgical instrument is widely used in all kinds of surgeries due to its advantages of accurate positioning, stable operation, dexterity, wide working range, fearlessness of radiation and infection, etc. During the operation, a plurality of robotic arms are controlled to move above a patient's body, and then perform the operation through an aperture pre-opened on the skin of the patient's body. The robotic arm is connected to an end effector by steel wires or steel straps, so that an end effector passes through the aperture on the skin of the patient's body and freely rotates around a point at the aperture.

<CIT> discloses a system for controlling an instrument that is inserted in a patient to enable a surgical procedure and controlled remotely from an input device controlled by a surgeon at a user interface, said system comprising: a base; a first link rotatably connected to said base; an elbow joint for rotatably connecting the second link to the first link; a handle; a wrist member connecting the handle to the distal end of the second link; and a controller coupled to at least said base and links and for receiving signals representative of; a rotational position of the base, a rotational position of the first link relative to the base, and a rotational position of the second link relative to the first link.

<CIT> relates to a medical instrument comprising at least one first, second and third joint member, at least two pairs of tendons connected with the same joint member and adapted to move said third member with respect to said second member, pulling it; and wherein each of said joint member comprises a main structural body comprising in a single piece one or more convex contact surfaces, all said convex contact surfaces defining with their prolongations thereof at least partially a single convex volume for each joint member; and wherein the main portion of each tendon is in contact with said jointed device only on said convex contact surfaces; and wherein at least two tendons of said at least two pairs of tendons are in contact with a same convex contact surface.

<CIT> discloses a medical device including a first link, a second link, and a band. A proximal end portion of the first link is coupled to a shaft. A proximal end portion of the second link is rotatably coupled to a distal end portion of first link about a first axis. The distal end portion of the second link includes a connector coupled to a tool member that is rotatable relative to the second link about a second axis that is non-parallel to the first axis. The first link defines a first guide channel and the second link defines a second guide channel. A distal end of the band is disposed within the first guide channel and the second guide channel, and is coupled to the tool member. The second link is rotatable relative to the first link about the first axis when the distal end of the band is moved.

<CIT> discloses a robotic arm is provided including a linkage assembly and a strap drive train. The linkage assembly includes first, second, third, and fourth links pivotally coupled in series together at first, second, and third joints to define a parallelogram with an insertion axis. The strap drive train includes first and second sets of straps coupled to the linkage assembly. As the linkage assembly is moved about a pitch axis, the first set of straps ensures the third link maintains the same angle relative to the first link, and the first and second set of straps ensures the fourth link maintains the same angle relative to the second link.

In general, the strap drive train employs straps and pulleys that are made from stainless steel with extremely high rigidity and compactness. The strap usually connects the pulley through a connector with a certain length. In a typical solution for rotation of the pulley over <NUM> degrees both clockwise and anticlockwise, as shown in <FIG>, two steel straps (straps <NUM>) are provided and wrap the pulley <NUM>' in opposite directions. Each of the straps connects the pulley through a connector <NUM> and then extends to wrap the periphery of the pulley. The two straps run parallelly and offset with respect to each other in a thickness direction of the pulley, so that the two straps wrap the pulley over <NUM> degrees in opposite directions. Accordingly, the pulley <NUM>' should have a thickness equal to or larger than the sum of the widths of the two straps to avoid overlapping of the two straps and interference between the two straps. The connector <NUM> is received in a groove <NUM>' recessed from the periphery to avoid between the connector and the internal parts of the robotic arm during rotation of the pulley. It is ensured that the connected <NUM>, when pulled, would not be detached from the pulley <NUM>' during the rotation of the pulley clockwise and anticlockwise over <NUM> degrees. In general, a larger angle at which the strap <NUM> wraps the pulley <NUM>' results in larger friction between the strap <NUM> and the pulley <NUM>' and thus a reduced tension on the strap <NUM>, thereby improving the safety margin.

Multiple robotic arms may be involved during the operation. Due to a small size of the aperture pre-opened on the skin of the patient's body, it is generally desirable that the robotic arm has a very compact structure and is thin enough to avoid interference between the robotic arms within a limited space. Typically, a joint, which connects the robotic arm and the end effector, includes an inner lug fixed on the end effector. As shown in <FIG>, the inner lug includes two tabs <NUM>' connecting the end effector (driven unit <NUM>) and the pulley <NUM>'. The pulley <NUM>' is fixed to the tabs <NUM>' which are integrally formed with the driven unit. Thus, the pulley <NUM>' is fixed to the driven unit <NUM> in such a way that the driven unit <NUM> is rotated by as much an angle as the pulley <NUM>' is rotated. In this solution, the tabs <NUM>' and the pulley <NUM>' are connected and inserted into an outer lug of the robotic arm. The tabs <NUM>' and the pulley <NUM>' are hinged to the outer lug through a pin, thereby achieving a connection between the end effector and an end of the robotic arm. The end of the robotic arm has a thickness of at least the sum of the thicknesses of the outer lug, the tabs <NUM>' and the pulley <NUM>'. It is difficult to realize both minimizing the thickness of the robotic arm and maximizing the rigidity of the robotic arm and the end effector, and thus tradeoffs between them are desirable.

Therefore, it is desirable to provide a compact structure in which the pulley and the driven unit are connected.

The present disclosure aims to provide a pulley and a structure including the pulley connected with a driven unit to resolve the conflict between the minimization of the thickness and maximization of the rigidity of the connection between the end effector and the robotic arm and thus to achieve both a small thickness and a large rigidity.

In order to solve the aforementioned problem, embodiments of the present disclosure provide solutions according to independent claim <NUM>.

A pulley is provided and includes a wheel portion and a lug portion. The wheel portion includes two circular end surfaces opposing each other and a side surface connecting the two end surfaces. The side surface includes a main arc face and a branch arc face. The branch arc face has a head end connected to the main arc face and a tail end configured to connect a strap. The branch arc face has a width in an axial direction of the wheel portion smaller than a width of the main arc face. The branch arc face and the main arc face form a continuous circular arc surface on which the strap rides. The lug portion is fixed to the wheel portion. The lug portion is disposed at a position adjacent to the branch arc face along the width of the main arc face and extends to protrude beyond the branch arc face in a radial direction of the wheel portion. The lug portion is configured to connect the pulley to a driven unit.

In an embodiment, the lug portion includes a first end surface adjacent to and perpendicular to the branch arc face, a second end surface opposite to the first end surface, a first side surface connecting the first end surface and the second end surface and extending from the main arc face, a top surface connecting the first end surface and the second end surface and disposed at a top of the pulley, and a second side surface disposed above the branch arc face and connecting the top surface. The top surface is configured to be attached to a surface of the driven unit.

In an embodiment, a connector chamber is provided at the tail end of the branch arc face and configured to receive and hold a strap connector connected to the strap.

In an embodiment, the connector chamber includes an abdomen and a mouth sized smaller than the abdomen, and the mouth opens to the branch arc face.

In an embodiment, the mouth has a top connecting the second side surface, and the top surface is disposed above the connector chamber and spaced from the connector chamber.

In an embodiment, two branch arc faces and two lug portions are provided, and the pulley is rotated-symmetrical about the radial direction of the wheel portion.

In an embodiment, each of the two branch arc faces has a central angle larger than <NUM>°.

In an embodiment, the main arc face has a central angle of <NUM>°, the width of each of the two branch arc faces is half that of the main arc face, the two branch arc faces partly overlap in the axial direction of the wheel portion and share the main arc face.

In an embodiment, the first side surface of the lug portion transitions smoothly to the main arc face.

A structure is provided and includes a driven unit and a pulley according to any one of the aforementioned embodiments. The pulley is connected to the driven unit through the lug portion.

In an embodiment, the driven unit is an end effector for a robotic arm.

Compared with the related art, in the pulley and the structure including the pulley and the driven unit connected to each other according to the embodiments of the present disclosure, an integrally formed pulley is provided with a simpler structure, in which the wheel portion is improved for wrapping of the strap and an additional lug portion is provided on the wheel portion, the pulley is fixed to the driven unit through the lug portion integrally formed with the wheel portion, so that components such as the tabs of the inner lug employed in the existing technology can be omitted. In this way, the thickness of the connection of the pulley is reduced, and a compact structure including the pulley and the driven unit is achieved, resulting in a smaller size and a lower weight of the robotic arm and thus improving operative accuracy during the surgeries.

To illustrate the technical solutions according to the embodiments of the present disclosure more clearly, the accompanying drawings for describing the embodiments are introduced briefly in the following. It should be appreciated that the accompanying drawings in the following description are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings from the accompanying drawings without creative efforts.

Reference numerals refer to:
pulley <NUM>, wheel portion <NUM>, main arc face <NUM>, branch arc face <NUM>, connector chamber <NUM>, circular end surface <NUM>, mounting hole <NUM>, lug portion <NUM>, first end surface <NUM>, first end surface on the left <NUM>-<NUM>, first end surface on the right <NUM>-<NUM>, second end surface <NUM>, second end surface on the left <NUM>-<NUM>, second end surface on the right <NUM>-<NUM>, first side surface <NUM>, top surface <NUM>, main connection surface <NUM>, intermediate connection surface <NUM>, wiring hole <NUM>, second side surface <NUM>, driven unit <NUM>, strap <NUM>, strap connector <NUM>, robotic arm housing <NUM>, pulley <NUM>', groove <NUM>', and tabs <NUM>'.

In the following description, several embodiments of the present disclosure are shown by example. It should be appreciated that other embodiments may be derived with changes in mechanical component, structure, electrical, and operation without departing from the spirit and scope of the present disclosure. The following detailed description is not intended to limit the present disclosure, and the scope of embodiments of the present disclosure is limited by the claims.

All directional indications (such as upper, lower, left, right, front, rear, etc.) in embodiments of the present disclosure are used only to explain relative positional relationships, motion situations, etc., between components under a particular posture (as shown in the drawings), and will change accordingly if the particular posture changes.

In that present disclosure, expressions concerning "first," "second," etc., are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implying the number of technical features indicated. Thus, features defined with "first," "second" may explicitly or implicitly include at least one of such features.

In that present disclosure, unless otherwise specified and defined, the terms "connect," "fix" and the like should be understood broadly, for example, the expression concerning "connect" may be referred to a fixed connection, a detachable connection, or an integral form, may be a mechanical connection or an electrical connection, may be a direct connection or an indirect connection with an intermediate component, may be a communication between interiors of two components or an interaction between two components. For those skilled in the art, the specific meaning of the above terms in the present disclosure may be understood by case.

In addition, the technical solutions in the various embodiments of the present disclosure may be combined with each other on the basis of practicability for those skilled in the art. The combination which causes conflicts should be considered as nonexistent and does not fall within the protection scope as claimed by the present disclosure.

As shown in <FIG>, an embodiment of the present disclosure provides a pulley <NUM> including a wheel portion <NUM> and a lug portion <NUM>. The wheel portion <NUM> is substantially cylindrical and includes two opposite circular end surfaces <NUM> and a side surface connecting the two circular end surfaces <NUM>. The side surface includes a main arc face <NUM> and at least one branch arc face <NUM>. The branch arc face <NUM> has a head end connected to the main arc face <NUM>. In an axial direction of the wheel portion, the branch arc face <NUM> has a width smaller than that of the main arc face <NUM>, The branch arc face <NUM> and the main arc face <NUM> form a continuous circular arc surface. The lug portion <NUM> is fixed to the wheel portion <NUM> and is disposed at a position adjacent to the branch arc face <NUM> along the width of the main arc face <NUM> and extends to protrude beyond the branch arc face <NUM> in a radial direction of the wheel portion <NUM>.

Further referring to <FIG>, in the pulley <NUM>, the branch arc face <NUM> further includes a tail end configured to connect a strap <NUM> which rides on the continuous circular arc surface formed by the branch arc face <NUM> and the main arc face <NUM>. The lug portion <NUM> is configured to connect the pulley <NUM> to a driven unit <NUM>.

In this embodiment, the main arcuate surface <NUM> and the branch arc face <NUM> forms the continuous circular arc surface for wrapping of the strap <NUM>. Compared with the typical pulley which is merely shaped as a wheel, the pulley according to the embodiment of the present disclosure includes, not only the wheel portion <NUM> which is substantially cylindrical and has the main arcuate surface <NUM> and the branch arc face <NUM>, but also the lug portion <NUM> which protrudes from the wheel portion <NUM> and configured to be fixed to the driven unit. Compared with the existing technology, the present disclosure provides an integrally formed pulley which is simpler in structure, in which the wheel portion <NUM> is improved for wrapping of the strap <NUM> and an additional lug portion <NUM> is provided on the wheel portion <NUM>, the pulley is fixed to the driven unit <NUM> through the lug portion <NUM> integrally formed with the wheel portion <NUM>, so that components such as the tabs <NUM>' of the inner lug as shown in <FIG> can be omitted. In this way, the thickness of the connection of the pulley <NUM> is reduced, and a compact structure including the pulley <NUM> and the driven unit <NUM> is achieved, resulting in a smaller size and a lower weight of the robotic arm and thus improving operative accuracy during the surgeries.

In an embodiment, the lug portion <NUM> includes a first end surface <NUM> adjacent to and perpendicular to the branch arc face <NUM>, a second end surface <NUM> opposite to the first end surface <NUM>, a first side surface <NUM> connecting the first end surface <NUM> and the second end surface <NUM> and extending from the main arc face <NUM>, a top surface <NUM> connecting the first end surface <NUM> and the second end surface <NUM> and disposed at a top of the pulley <NUM>, and a second side surface <NUM> disposed above the branch arc face <NUM> and connecting the top surface <NUM>. The top surface <NUM> is, for example, flat and is configured to be attached to a surface (for example, which is also flat) of the driven unit <NUM>, so that the pulley <NUM> is fixed to the driven unit <NUM>. As an example, the top surface <NUM> is fixed to the flat surface of a main arm of the driven unit <NUM> by mechanical connection or welding, or is integrally formed with the main arm of the driven unit <NUM>.

In this embodiment, with the reasonable design of the lug portion <NUM>, the pulley <NUM> is connected to the driven unit <NUM> through the connection of two flat surfaces. While in the existing technology, the connection between the pulley and the driven unit is realized by inserting the pulley between tabs of the driven unit, which may become loose during a long-term operation. The solution provided in the embodiment of the present disclosure avoids such problems during the long-term operation, and thus improves the reliability.

In an embodiment, a connector chamber <NUM> is provided at the tail end of the branch arc face <NUM> and configured to receive and hold a strap connector <NUM> which is connected to the strap <NUM>. For example, the strap connector <NUM> is matched in shape with the connector chamber <NUM>. The connector chamber <NUM> includes an abdomen and a mouth sized smaller than the abdomen, and the mouth opens to the branch arc face <NUM>. In a specific application, the strap connector <NUM> is received in the connector chamber <NUM>, and the strap <NUM> extends out of the connector chamber <NUM> through the mouth and further extends along and rides on the branch arc face <NUM>.

In this embodiment, the connector chamber <NUM> with a large abdomen and a small mouth is provided to connect the strap connector <NUM> without requiring any additional fastener such as screws, which simplifies the connection of the strap connector, and contributes to the reasonable design of the lug portion <NUM> on the wheel portion <NUM>.

In an embodiment, the mouth of the connector chamber <NUM> has a top connecting the second side surface <NUM>, and the top surface <NUM> is disposed above the connector chamber <NUM> and spaced from the connector chamber <NUM>. In this way, with such a simple structure, it is effectively ensured that no interference occurs between the strap connector and the robotic arm or the driven unit <NUM> during operation.

In an embodiment, the pulley <NUM> is rotated-symmetrical about the radial direction of the wheel portion <NUM> (i.e., the broken line L as shown in <FIG>). Each of the left and right sides of the pulley <NUM> includes a branch arc face <NUM>, a connector chamber <NUM> and a lug portion <NUM>, so that the two straps <NUM> are connected to the pulley and run in opposite directions. Specifically, the first end surfaces <NUM> (i.e., a first end surface <NUM>-<NUM> on the left and a first end surface <NUM>-<NUM> on the right as shown in <FIG>), the second end surfaces <NUM> (i.e., a second end surface <NUM>-<NUM> on the left and a second end surface <NUM>-<NUM> on the right as shown in <FIG>) and the second side surfaces <NUM> (not indicated with separate reference numerals) of the two lug portions <NUM> are also rotated-symmetrical. The rotated-symmetrical structure makes it possible to connect the straps <NUM> at both sides, and contributes to force balancing.

In an embodiment, each of the two branch arc faces <NUM> has a central angle larger than <NUM>°, so that the pulley <NUM> is driven by the straps <NUM> to rotate both clockwise and anticlockwise by over <NUM>°. In an embodiment, the main arc face111 has a central angle of <NUM>°. The width of each of the two branch arc faces <NUM> is half that of the main arc face <NUM>. The two branch arc faces <NUM> partly overlap in the axial direction of the wheel portion <NUM> and share the main arc face <NUM>. In this way, the wheel portion <NUM> has a simple structure. In an embodiment, the first side surface <NUM> of the lug portion <NUM> transitions smoothly to the main arc face <NUM> and extends in a direction away from the main arc face <NUM> to be lifted from a plane that is tangent to the main arc face <NUM> at the connection between the main arc face <NUM> and the first side surface <NUM>. In this way, the pulley <NUM> has a smooth outline, and the connection area between the pulley <NUM> and the driven unit <NUM> is increased. In an embodiment, the top surface <NUM> includes a main connection surface <NUM> on each side and an intermediate connection surface <NUM> connecting the main connection surfaces <NUM>. In an embodiment, a wiring hole <NUM> is provided and opens at the top surface <NUM> for allowing wires to pass therethrough and enter the driven unit <NUM>. In an embodiment, the mounting hole <NUM> penetrates through the two circular end surfaces in the axial direction of the wheel portion <NUM>. The mounting hole <NUM> allows a rotary shaft of the robotic arm to be inserted therein.

In the above embodiments, with cooperation of the lug portion <NUM> and the connector, the pulley <NUM> can achieve the connection between the connector and the lug portion <NUM> and the normal wrapping of the strap, and the driven unit <NUM> is rotatable by a large angle with driven of the pulley <NUM>. Meanwhile, the thickness of the robotic arm is reduced and the rigidity of the connection between the robotic arm and the end effector is increased. Further, no interference with the robotic arm occurs in the subsequent installation.

As shown in <FIG>, an embodiment of the present disclosure provides a structure including a pulley and a driven unit connected to each other. The pulley <NUM> is connected to the driven unit <NUM> through the lug portion <NUM>. For example, the lug portion <NUM> is fixed to the driven unit <NUM> by mechanical connection or welding, or is integrally formed with the driven unit <NUM>. For example, the top surface <NUM> of the lug portion <NUM> is attached to a flat surface of the driven unit <NUM>. The driven unit <NUM> may be an end effector for a robotic arm, particularly an end instrument holder of a surgical robot. The strap connector <NUM> at the end of the strap <NUM> is held in the connector chamber <NUM> below the top surface <NUM>, and the second side surface <NUM> provides a safe distance for avoiding interference between the strap connector and the driven unit <NUM>. The pulley <NUM> is fixed to the driven unit <NUM> as shown in <FIG> and <FIG>, and then the strap connector <NUM> is inserted into the connector chamber <NUM> as shown in <FIG>, and then a rotary shaft is inserted into the mounting hole <NUM>, and the pulley <NUM> is sandwiched by the robotic arm housing <NUM>, as shown in <FIG>. As shown in <FIG>, an embodiment of the present disclosure provides a robotic arm having the structure. The robotic arm may be used in a surgical robot.

In this structure, the connection of the driven unit <NUM> and the pulley <NUM> are "half-connected," that is, two straps <NUM> each wraps about a half of the pulley <NUM> on the left side or right side, and the lug portion <NUM> without strap <NUM> wrapping thereon is connected to the driven unit <NUM>. In this way, the thickness of the connection is greatly reduced as the tabs of the end effector used in the existing surgical robot is omitted, resulting in a reduced thickness of the end link of the robotic arm and a compact connection with higher rigidity.

In <FIG>, the pulley is rotated-symmetrical about the radial direction of the wheel portion <NUM> with being hollowed at the front upper left and the rear upper right, or at the front upper right and the rear upper left. The straps <NUM> are connected to the lug portion and extend to ride on the wheel portion within the hollows. In this way, the thickness of the link of the robotic arm is greatly reduced. The rigidity of connection is increased as the connection area between the lug portions and the end effector.

In an embodiment, the strap <NUM> may include a steel strap, or other flexible transmission mechanisms such as belts, ropes, or the like. During running of the strap, the pulley rotates by less than a round. The lug portion for connection with the driven unit is disposed at a same level in the width of the pulley as the strap, resulting an improved efficiency in space utilization. Those having the same concept as the present disclosure are considered as variants to the embodiments of the present disclosure.

Claim 1:
A pulley, applicable to a robotic arm, comprising:
a wheel portion (<NUM>) including two circular end surfaces (<NUM>) opposing each other and a side surface connecting the two end surfaces (<NUM>), wherein the side surface includes a main arc face (<NUM>) and a branch arc face (<NUM>), the branch arc face (<NUM>) has a head end connected to the main arc face (<NUM>) and a tail end configured to connect a strap (<NUM>), the branch arc face (<NUM>) has a width in an axial direction of the wheel portion smaller than a width of the main arc face (<NUM>), and the branch arc face (<NUM>) and the main arc face (<NUM>) form a continuous circular arc surface on which the strap (<NUM>) rides; and
a lug portion (<NUM>) fixed to the wheel portion (<NUM>), wherein the lug portion (<NUM>) is disposed at a position adjacent to the branch arc face (<NUM>) along the width of the main arc face (<NUM>) and extends to protrude beyond the branch arc face (<NUM>) in a radial direction of the wheel portion (<NUM>), and the lug portion (<NUM>) is configured to connect the pulley (<NUM>) to an end effector of the robotic arm;
wherein
two branch arc faces and two lug portions are provided, and
characterized in that
each of left and right sides of the pulley (<NUM>) comprises a connector chamber (<NUM>), one of the two branch arc faces (<NUM>) and one of the two lug portions (<NUM>), the connector chamber (<NUM>) being configured to receive and hold a strap connector which is connected to a strap and matched in shape with the connector chamber, and the pulley (<NUM>) is rotated-symmetrical about the radial direction of the wheel portion (<NUM>) so that two straps (<NUM>) are connectable to the pulley at both sides and along opposite directions.