Description:[001] The present invention relates to an article that includes a limb component. More specifically, the present invention refers to an article that includes a limb component with a composite structure.

Background of the Invention

[002] Limb components, especially for robots are well known in the art. More specifically, limb components for quadruped robots are being studied, and various designs are described in the art. For example, US patent application US20210283783 describes a modular robotic service vehicle which includes a chassis and body, and comprising one or more robotic arms or legs capable of stepping, and walking Chinese patent application CN112660265 describes a biped robot leg structure.

[003] However, one of the shortcomings of prior art systems such as those described above, is that, in order to be able to carry a payload, these robotic limbs are required to have good mechanical strength, thus increasing the weight of the robot. There is hence, a need for the development of robotic limbs that have a combination of good mechanical strength and low weight.

Summary

[004] One embodiment of the present invention is an article that includes a limb component. The limb component includes a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate. The limb component has a balance of bending strength and weight.

[005] Another embodiment of the present invention is a robotic limb having a limb component. The limb component includes a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate, wherein the component has a balance of bending strength and weight.

Description of Drawings

[006] Figure 1 is a drawing of a limb component according to an embodiment of the present invention.

[007] Figure 2 is a drawing showing an exploded view of a limb component according to an embodiment of the present invention.

[0001] Figure 3 is a drawing of a limb component according to an embodiment of the present invention, showing the thigh and shank separately

[008] Figure 4 is a drawing of a tensioner assembly according to an embodiment of the present invention.

[009] Figure 5 is a drawing showing the exploded view of a tensioner assembly according to an embodiment of the present invention.

[010] Figure 6 is a drawing showing the exploded view of a thigh according to an embodiment of the present invention.

[011] Figure 7 is a drawing showing the exploded view of a shank according to an embodiment of the present invention.

Detailed Description

[012] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.

[013] In the specification and the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:

[014] The singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. “Substantially” means a range of values that is known in the art to refer to a range of values that are close to, but not necessarily equal to a certain value.

[015] Other than in the examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term “about.” In some aspects of the current disclosure, the terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art.

[016] As used herein, the term “substantially” and its variations are defined as being largely but not necessarily wholly what is specified as understood by one of ordinary skill in the art.

[017] Various numerical ranges are disclosed herein. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations, and not to be considered as limiting the scope of the invention.

[018] As used herein, the term “robotic limb” refers to a mechanical limb that can perform the same functions as a human or animal limb. The robotic limb may be controlled by electronic means.

[019] As used herein, the term “quadruped” refers to an entity that possesses four legs. Specifically, here, quadruped may refer to a quadruped robot, i.e. a four-legged robot.

[020] As used herein, the term “limb component” refers to a part of a limb, such as a thigh, a shank, an upper arm, or a forearm.

[021] As used herein, the term “tensioner assembly” refers to an assembly that serves to maintain tension at the joints of the limb component. Specifically, the term “tensioner assembly” refers to an assembly that serves to maintain tension at the elbow joint or the knee joint of the limb component.

[022] As used herein in one embodiment of the present invention, the term “sandwiched” may refer to a filler material placed between two surfaces.

[023] One embodiment of the present invention is an article that includes a limb component having a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate, wherein the component has a balance of bending strength and weight.

[024] Referring now to Figure 1, a drawing of a limb component 100 according to an embodiment of the present invention is shown. The limb component 100 includes an abduction actuator 102, abduction to hip coupling 104, a hip actuator 106, a hip to knee coupling 108, a knee actuator 110, a knee sprocket coupling assembly 112 not shown in the Figure 1, a thigh link 114 and a shank link 116. The thigh link 114 and shank link 116 are attached to each other through the knee joint, which includes the hip to knee coupling 108, the knee actuator 110, and the knee sprocket coupling assembly 112. As described in an example embodiment of the present invention, the thigh link 114, shank link 116, or thigh and shank link may include a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate.

[025] Referring now to Figure 2, an exploded view of a limb component 200 according to an embodiment of the present invention, is shown. The exploded view of the limb component 200 includes an abduction actuator 202, abduction to hip coupling 204, a hip actuator 206, a hip to knee coupling 208, a knee actuator 210, a knee sprocket coupling assembly 212, a thigh link 214 and a shank link 216.

[026] Referring now Figure 3, the thigh link 302 and the shank link 304 of limb component 300 according to an embodiment of the present invention, are shown separately. Figure 3 shows the thigh link 302 and the shank link 304 more clearly, and also shows how the shank link 304, and the thigh link 302 are connected at the knee joint.

[027] In an embodiment of the present invention, the first metal plate may be made of a metal. In an embodiment of the present invention, the first metal plate may be made of iron, steel, aluminium, titanium, and alloys thereof.

[028] In an embodiment of the present invention, the filler material may be plastic or wood.

[029] In an embodiment of the present invention the filler material may be a polymer. In another embodiment of the present invention, the filler material may be a thermoplastic polymer. In yet another embodiment of the present invention, the filler material may be a polyamide, a polyolefin, a polyethylene, a polypropylene, a polycarbonate, a polyester, a polyethylene terephthalate (PET), an polybutylene terephthalate (PBT), an acrylonitrile-butadiene-styrene (ABS), a polyvinyl chloride (PVC), and mixtures, blends, and copolymers thereof. As used herein, the term “mixture” or “blend” may refer to a physical mixture of two or more polymers, while the term “copolymer” may refer to two or more monomers polymerized together to form a copolymer. In another embodiment of the present invention, the filler material may be a thermosetting polymer. In yet another embodiment of the present invention, the filler material may be a phenol-formaldehyde resin, an epoxy resin, a polyurethane resin, a urea-formaldehyde resin, a melamine resin, and mixtures and copolymers thereof.

[030] In an embodiment of the present invention, the filler material may be wood. In an embodiment of the present invention, the filler material may be a hardwood or a softwood. In an embodiment of the present invention, the filler material may be a softwood. In another embodiment of the present invention, the filler material may be balsa wood, cedar, pine, fir, or redwood. In an embodiment of the present invention, the filler material may be a hardwood. In another embodiment of the present invention, the filler material may be birch, chestnut, oak, mahogany, ebony or walnut. In another embodiment of the present invention, the filler material may be plywood. In yet another embodiment of the present invention, the filler material may be engineered wood. In an embodiment of the present invention, the filler material may be a combination of different types of wood.

[031] In an embodiment of the present invention, the first metal plate may be made of a metal. In an embodiment of the present invention, the first metal plate may be made of iron, steel, aluminium, titanium, and alloys thereof.

[032] In an embodiment of the present invention, the first metal plate and the second plate may be made of the same metal. In another embodiment of the present invention, the first metal plate and the second plate may be made of different metals.

[033] In an embodiment of the present invention, the first metal plate and the second metal plate and the filler material may be attached to each other by means of a fastener. In another embodiment of the present invention, the fastener may be an adhesive. In yet another embodiment of the present invention, the adhesive may be an epoxy adhesive, an acrylate adhesive, a cyanoacrylate adhesive, a hot-melt adhesive, a resin-based adhesive, a polyurethane based adhesive, an elastomer based adhesive, a silicone based adhesive, a thermoset adhesive, an UV curing adhesive, an anaerobic adhesive, and combinations thereof.

[034] In yet another embodiment of the present invention, the fastener may be a screw, a nut and bolt, a rivet, and pluralities and combinations thereof. In another embodiment of the present invention, the first metal plate and the second metal plate and the filler material may be attached to each other by means of a plurality of fasteners.

[035] In an embodiment of the present invention, the filler material has a thickness in range of 20 millimetres to 120 millimetres.

[036] In an embodiment of the present invention, the article is a robotic limb.

[037] In an embodiment of the present invention, the limb component may have a balance of bending strength and weight. In an embodiment of the present invention the limb component may have a good bending strength, i.e. ability to withstand a bending force without breaking, while having a low weight as compared to a limb component made of metal.

[038] In an embodiment of the present invention, the article comprises a tensioner assembly.

[039] In an embodiment of the present invention, the tensioner assembly includes at least two tensioner joints, a roller chain and a fastener connecting the at least two tensioner joints.

[040] Referring now to Figure 4, a drawing of a tensioner assembly according to an embodiment of the present invention is shown. The tensioner assembly includes the chains 404a and 404b. The tensioner assembly is made of two identical parts called the tensioner joints 402a, 402b. They are joined together through two fasteners 406a, 406b. The tensioner joints 402a, 402b connect the two ends of the chains. The fasteners 406a, 406b may be nut-bolts, or rivets. The tensioner assembly serves to maintain a tension on the chains 404a, 404b, that serve to transmit power to the knee, during actuation of the knee joint, thus enabling locomotion of the robot.

[041] Referring now to Figure 5, a drawing showing the exploded view of a tensioner assembly according to an embodiment of the present invention is shown. The tensioner joints 502a, 502b chains 504a, 504b and fasteners 506a and 506b are more clearly shown in the Figure 5.

[042] Another embodiment of the present invention is a robotic limb comprising, a limb component comprising a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate, wherein the component has a balance of bending strength and weight.

[043] In one embodiment of the present invention the limb component is a thigh, a shank, an upper arm, a forearm, or combinations thereof.

[044] Referring now to Figure 6, a drawing showing the exploded view of a thigh 600 according to an embodiment of the present invention is shown. The thigh 600 includes the inner thigh plate 602, outer thigh plate 604, hip sprocket support shaft 606, hip sprocket support shaft fastening module 608, a pair of upper central spacers 610a-b, a pair of lower central spacers 612a-b, a pair of knee joint strengthening plates 1614a-b, a pair of knee joint rotary bearings 616a-b, a pair of knee joint bearing retainers 618a-b, a knee bolt 620 and nut 622.

[045] In an embodiment of the present invention, the outer thigh plates and the inner thigh plates may be made of metal and the central spacer may be made of a filler material.

[046] In an embodiment of the present invention, the ratio of weight of the limb components to the weight of the robot may be from about 10 percent to about 40 percent. In an embodiment of the present invention, the ratio of weight of the limb components to the weight of the robot is about 20 percent.

[047] In one embodiment of the present invention, the inner and outer thigh plate form the main structure of the thigh link. The following is an example embodiment of the arrangement of the components of the robotic leg of the present invention. The inner thigh plate has a big circular opening at one end of its length. The knee actuator gets attached to the inner thigh plate around this large circular opening. The outer thigh plate has a hip sprocket support shaft attached to it. It is on the inside of the thigh link assembly, and gets fastened to the outer thigh plate using the hip sprocket support shaft fastening module, which is on the outside of the thigh link assembly using fasteners. As discussed earlier the bearing in the hip sprocket assembly takes support from the hip sprocket support shaft. The upper and lower central spacers are sandwiched between the inner and the outer thigh plates using glue and fasteners. The spacers join the inner and outer thigh plates to provide thickness to the thigh link. The upper central spacer also covers the top of the thigh link and in-turn protects the hip sprocket assembly from outer debris. The lower central spacers join the inner and outer thigh plates from just below the mounting of the knee actuator, near the hip joint, and join them till a point near the knee joint such that the knee sprocket has just enough clearance to rotate freely. This ensures that the inner and outer thigh links are tightly bounded to each other and provides resistant against the moments generated at the knee joint, due to contact of the foot with the ground. The pair of knee joint strengthening plates strengthen both the inner and outer thigh links at the knee joint, and is attached to them using glue and fasteners on the outside of the thigh link. It prevents them from bending due to forces at the knee joint. There is a small circular hole in the inner and outer thigh plates and the knee joint strengthening plates which are all concentric to each other and also to the knee joint. There are a pair of knee joint rotary bearings each attached to the inner and outer thigh plates using the knee joint bearing retainers, which also retains the bearing. The shank assembly rotates on these bearings on the either side. Then there is the knee bolt which goes through the axial holes of the knee sprocket couplings, which are a part of the shank assembly. These knee sprocket couplings take support on the knee rotary beatings. The knee bolt is fastened using a knee nut on the other side of the thigh link. Together the knee nut and bolt prevent the thigh assembly against the opening up in the knee joint axial direction, under the twist loads at the knee joint.

[048] Referring now to Figure 7, a drawing showing the exploded view of a shank 700 according to an embodiment of the present invention is shown. The shank 700 includes a pair of outer shank plates 702a-b, a central spacer 704, the knee sprocket 706, a pair of knee sprocket couplings 708a-b, knee strengthening supports 710a-b, and a foot padding 712.

[049] In an embodiment of the present invention, the outer shank plates and the inner shank plates may be made of metal and the central spacer may be made of a filler material.

[050] In one example embodiment of the present invention, the outer shank plates provide the strength and structure to the shank link. The central spacer is sandwiched between the two outer shank plates using glue and fasteners. This provides thickness to the shank link. The knee strengthening supports provide strength to the shank at the knee joint. They are sandwiched between the outer shank plates and the central spacer and joined by glue and fasteners. The knee sprocket assembly consists of 3 parts, one knee sprocket and two knee sprocket couplings attached to the sprocket on each side. The knee sprocket couplings have a hub through which they get connected to the sprocket and a stepped shaft which takes support on the knee rotary bearing which is the part of the thigh link assembly. There is also an axial hole in both the knee sprocket couplings and the knee sprocket through the knee bolt passes through, as discussed earlier. The knee sprocket assembly is attached to the knee strengthening supports which in-turn are attached to the outer shank plates. There is a small circular hole in both the outer shank plates and the knee strengthening supports which are all concentric to each other and to the knee joint. The shaft of the knee sprocket assembly passes through these circular openings. The step on the knee sprocket coupling helps to restrict the axial motion of the shank at the knee joint, by resting the step against the inner wall of the rotary bearings at the knee joint. There is a foot padding attached at the bottom of the shank link. This is made up of soft material that ensures that the high impact forces while walking are minimized, to reduce the impact loading the thigh and the shank link.

[051] Advantages:

1. The article of the present invention is light weight.
2. The article of the present invention has good mechanical strength.
3. The article of the present invention does not require expensive manufacturing methods such as CNC machining.
4. The quadruped robot that includes a limb component according to an embodiment of the present invention is light weight, strong, and capable of carrying heavy payloads. The ratio of weight of the limb components to the weight of the robot is about 20%.

[052] It is to be understood that the above described embodiments are merely illustrative of numerous and varied other embodiments which may constitute applications of the principles of the invention. Such other embodiments may be readily understood by those skilled in the art without departing from the spirit or scope of this invention.
, Claims:We claim:

1. An article comprising, a limb component comprising a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate, wherein the component has a balance of bending strength and weight.
2. The article as claimed in claim 1, wherein the first metal plate and the second metal plate are selected from iron, steel, titanium, aluminium or alloys thereof.
3. The article as claimed in claim 1, wherein the filler material is selected from wood, polymer or combinations thereof.
4. The article as claimed in claim 1, wherein the filler material has a thickness in range of 20 millimetres to 120 millimetres.
5. The article as claimed in claim 1, wherein the article is a robotic limb.
6. The article as claimed in claim 1, wherein the article comprises a tensioner assembly.
7. The article as claimed in claim 7, wherein the tensioner assembly comprises at least two tensioner joints, a roller chain and a fastener connecting the at least two tensioner joints.
8. A robotic limb comprising, a limb component comprising a first metal plate and a second metal plate and a filler material arranged between the first metal plate and the second metal plate, wherein the component has a balance of bending strength and weight.
9. The robotic limb as claimed in claim 9, wherein the limb component is a thigh, a shank, an upper arm, a forearm, or combinations thereof.