FIELD OF THE INVENTION

[001] The present invention is generally related to universal joints. More particularly, the present invention relates to cross linking members, for universal joints, with round or curved surfaces at end sections.

BACKGROUND OF INVENTION

[002] A universal joint is a positive, mechanical connection between rotating shafts, which are usually not parallel, but intersecting. They are used to transmit motion, power, or both. The simplest and most common type is called the Cardan joint or Hooke joint. It consists of a cross element and two yokes coupled with the cross element. Each shaft is connected with the cross element via the yoke. The angle between the two shafts is generally inclined, and is sometimes referred to as operating angle.

[003] Universal joints are available in steel or in thermoplastic body members. Universal joints made of steel have maximum load-carrying capacity for a given size. Universal joints with thermoplastic body members are used in light industrial applications in which their self-lubricating feature, light weight, negligible backlash, corrosion resistance and capability for high-speed operation are significant advantages. [004] There are different types of universal joints available presently. For example, universal joint pin type, needle bearing universal joint, spline type universal joints, joints with multiple forks, joints for two shafts connector, needle type universal joints among others. Typical applications of universal joints include aircraft, appliances, control mechanisms, electronics, Instrumentation, medical and optical devices, ordnance, radio, sewing machines, textile machinery and tool drives. Agriculture and farming is also one of the common applications of universal joints. [005] While running for longer periods, the universal joints need to be applied with lubricant, such as grease or other such materials for all the friction areas. Specially, the areas where the yokes connect and turn around the cross member. Due to heavy loads, and longer running, lubrication of parts becomes the most important task for maintaining the universal joints. However, due to continuous longer operations the lubricant, such as grease, in the universal joints gets consumed. Also, due to continuous exposure of the universal joints to harsh environment of operation, such as in dust, dirt, heat etc., the lubrication of the friction areas gets consumed quickly. Therefore, one needs to apply the lubricant, such as grease or other such thick oil etc. regularly to maintain the parts of the universal joints, and avoid them from getting worn out.

[006] Furthermore, generally the universal joints consist of needle bearings around the connection between the cross member and the yokes. The yokes continuously turn around the needle bearings of the cross member. Such movement produces more friction due to which lubricant is exhausted more quickly. Hence, regular application of lubricant becomes more important. But due to needle bearings, the parts of the universal joints experience more friction and chances of getting worn and torn out become higher. This increases cost of maintenance and wearing and tearing out.

[007] Therefore, there is a need for an improved in the universal joints, where friction can be avoided to a greater extent, further reducing chances of wearing and tearing out and hence, cost of maintenance can be reduced. SUMMARY OF THE INVENTION

[008] It is an objective of the present invention to provide an improved intermediate linking member for a universal joint that comprises ball shaped ends forming joints.

[009] An objective of the present invention is to provide an improved universal joint in which yokes are engaged with the intermediate linking member around the ball shaped ends of the intermediate linking member, and the yokes rotate on the ball shaped ends of the intermediate linking member, thereby less friction is produced at the engagement during rotation. [0010] An objective of the present invention is to provide an improved intermediate linking member for universal joints which reduces friction around the engagement joints between the intermediate linking member and the yokes or connecting shafts, and in turn reduces frequent application of lubricant on parts around the engagement, thereby reducing costs of maintenance.

[0011] An aspect of the present invention provides an intermediate cross-linking member for a universal joint, comprising at least two intersecting arms, each arm having two opposing distal ends; and at least one arm of the at least two intersecting arms having a curved shape of at least one of the two opposing distal ends, wherein the curved shape of the at least one of the two opposing distal ends reduce friction at an engagement point at which the at least one arm of the at least two intersecting arms engage with at least a yoke or at least a connecting arm or at least a connecting shaft via the two opposing distal ends of the at least one arm.

[0012] Another aspect of the present invention provides a linkage assembly for transmitting power and motion comprising: an intermediate cross-linking member for a universal joint, including: at least two intersecting arms, each arm having two opposing distal ends; and at least one arm of the at least two intersecting arms having a curved shape of at least one of the two opposing distal ends; and at least a yoke or at least a connecting arm or at least a connecting shaft engaging with the intermediate cross-linking member via the two opposing distal ends of the at least one arm of the at least two intersecting arms, at engagement points, wherein the at least a yoke or at least a connecting arm or at least a connecting shaft is rotatable or hinge-ably rotatable, at the engagement points, over the curved shape of the two opposing distal ends of the at least one arm of the at least two intersecting arms, and wherein the curved shape of the two opposing distal ends reduce friction at the engagement points.

[0013] Another aspect of the present invention provides the at least two intersecting arms engage with at least two yokes or at least two connecting arms or at least two connecting shafts via the two opposing distal ends of the at least two intersecting arms, at four engagement points, for transmitting power and motion to rotating shafts.

[0014] Another aspect of the present invention provides the at least a yoke or at least a connecting arm or at least a connecting shaft is rotatable or hinge-ably rotatable, at the engagement point, over the curved shape of the at least one of the two opposing distal ends of the at least one arm of the at least two intersecting arms.

[0015] Yet another aspect of the present invention provides wherein the curved shape of at least one of the two opposing distal ends include ball like shape, hemisphere, spherical, elliptical, convex, cylindrical, concave, semi square with smooth round edges, or a round shape.

[0016] Yet another aspect of the present invention provides the at least two intersecting arms are at least two intersecting pins inserted into each other to form a cross shape or at least two hooks arrangement that are cross hinged with each other.

[0017] Another aspect of the present invention provides the curved shape of at least one of the two opposing distal ends maintain a separation between surfaces of the at least a yoke or at least a connecting arm or at least a connecting shaft and surface of the distal end, at the engagement point.

[0018] Another aspect of the present invention provides the curved shape of at least one of the two opposing distal ends is lubricated with a lubricant, the lubricant includes oil, grease, and other such conventional lubricant.

BRIEF DESCRIPTION OF DRAWINGS

[0019] For a better understanding of the embodiments of the systems and methods described herein, and to show more clearly how they may be carried into effect, references will now be made, by way of example, to the accompanying drawings, wherein like reference numerals represent like elements/components throughout and wherein: [0020] FIG. 1 illustrates an exemplary environment showing a perspective view of an intermediate linking member for a universal joint, in accordance with an embodiment of the present invention; and

[0021] FIG. 2 illustrates an exemplary environment showing an assembly of a linkage system for transmitting power or motion, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF INVENTION [0022] This patent describes the subject matter for patenting with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. The principles described herein may be embodied in many different forms.

[0023] Illustrative embodiments of the invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

[0024] The present invention provides an intermediate linking member for a universal joint, where the intermediate linking member comprises arms having ends with rolling or round surfaces. In an embodiment, the intermediate linking member may have curved or rounded shaped surfaces, such as ball shaped surfaces, or spherical shaped surfaces, or rollers or cylindrical shaped surfaces, or ovoid shaped etc. The intermediate linking member consists of two intersecting arms forming a cross, and hence has a cross shape. Each of the two intersecting arms has two distal ends. The four distal ends of the two intersecting arms have rolling or round surfaces. This further means that the intermediate linking member has four distal rolling or round ends that engage with two yokes or connecting arms or connecting shafts. The yokes or connecting arms or connecting shafts may be used interchangeably used in the description, which may mean any component that engage with the distal ends of the intersecting arms of the intermediate linking member, without deviating from the meaning and scope of the present invention. The yokes turn and rotate over the four distal rolling or round ends of the two intersecting arms of the intermediate linking member. Thereby, friction produced due to rotation (or operation) at the engagement of the two yokes with the four distal round ends of the two intersecting arms is greatly reduced because of the distal ends of the intermediate linking member having round or curved or rolling shapes.

[0025] FIG. 1 illustrates an exemplary environment showing a perspective view of an intermediate linking member for a universal joint, in accordance with an embodiment of the present invention. The exemplary environment 100 shows the intermediate linking member 102 comprises of two intersecting arms 104 and 106 forming a cross shape. Each of the two intersecting arms 104 and 106 has two opposing ends (104A and 104B; 106 A and 106B), which may be referred to as four distal ends of the intermediate cross-linking member 102. The four distal ends (104A and 104B; 106A and 106B) have rolling or round shaped edges 108, which means that the two intersecting arms 104 and 106 are round shaped at the four distal ends (104A and 104B; 106A and 106B). In another embodiment, the four distal ends (104A and 104B;

106 A and 106B) are provided with smooth curved shaped edges, where the curved shaped edges may have ball shaped, or round, or hemispherical, or spherical, or cylindrical, or elliptical, and the like.

[0026] It may be appreciated by a person skilled in the art that the intermediate linking member 102 may have different other formations other than being cross shaped, such as the intermediate linking member may comprise two pins, where one pin is inserted into another, and the pins have distal ends which have round shaped edges 108 or round edges 108, without deviating from the meaning and scope of the present invention.

[0027] Further, the intermediate linking member 102 with round edges 108 engages with two yokes or two connecting arms. The two yokes engage with the four distal ends (104A and 104B; 106A and 106B) of the two intersecting arms 104 and 106, where the four distal ends (104A and 104B; 106A and 106B) have round edges 108. Therefore, the yokes engage with the round edges 108 and rotate over the round edges 108. Due to rotation over the round edges 108 of the four distal ends (104A and 104B; 106A and 106B), friction is greatly reduced. The round edges 108 maintain the separation between the engaging surfaces, which are surfaces of the intersecting arms 104 and 106, and surfaces of the yokes, and reduce rotational friction and support radial and axial loads between the intersecting arms 104 and 106 and the yokes. Further, the round edges 108 are also lubricated sufficiently, to further reduce the friction due to rotation of the yokes on the intermediate linking member 102. [0028] FIG. 2 illustrates an exemplary environment showing an assembly of a linkage system for transmitting power or motion, in accordance with an embodiment of the present invention. The assembly of linkage system 200 comprises the intermediate linking member 102 and two connecting arms 202 and 204. The intermediate linking member 102 consists of the two intersecting pins or arms 104 and 106, each with opposing distal ends. The four distal ends of the two intersecting pins have round edges 108. The two connecting arms 202 and 204 engage with the two intersecting pins 104 and 106 with the round edges 108 in between and connect with the intermediate linking member 102. Further, the connecting arms 202 and 204 connect with the intermediate linking member 102 by engaging with the round edges 108 of the distal ends and the connecting arms 202 and 204 further rotate over the round edges 108 of the distal ends of the intermediate linking member 102.

[0029] The intermediate linking member 102 may be provided with any formation, such as a cross member, or two pins inserted into each other to form a cross shape, or hooks arrangement cross hinged with each other. In any of the formations, ends of the arms or hooks of the intermediate linking member 102 are provided with smooth round edges 108 or smooth curved surfaces. It may be appreciated by a person skilled in the art that the curved surfaces may be of any curved shape, such as ball, hemisphere, spherical, elliptical, convex, semi square with smooth round edges, round shape, etc, without deviating from the meaning and scope of the present invention. The curved surfaces are shaped such that when the connecting arms rotate over them, the friction produced due to continuous rotation is reduced greatly.

[0030] Advantageously, the present invention provides an intermediate linking member, for a universal joint, having arms with round edges at the end sections. The yokes or the connecting arms engage with the the linking member around the round edges at the end sections and rotate over the round edges of the end sections. Due to rotating over the round edges, friction that is produced due to rotation is greatly reduced. Parts of universal joint are able to continuously run for longer period without breaking down frequently due to wear and tear.

[0031] The lubricant applied on the round edges of the end sections does not get consumed quickly. Hence, the intermediate linking member with round edges allow for longer duration of operations, with less friction being produced, less frequent application of lubricants, and thereby reducing the cost of maintenance. Also, wear and tear of the parts of the universal joint is greatly reduced.

[0032] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the present disclosure. Indeed, the novel methods, devices, and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the methods, devices, and systems described herein may be made without departing from the spirit of the present disclosure.