Dual Axis V-Pivot license information

thingiverse

<b>Dual Axis V-Pivot.</b> The Open Source license for the Dual Axis V-Pivot is held by Sunnyvale Investments Group. Contact phone number +64 275 985 266 This invention is published under a Creative Commons - Attribution - Non Commercial - No Derivatives license. Other IP protection are currently being sought for this invention but will not limit or constrain or contradict this Creative Commons license. <b>Field of Invention.</b> The present invention relates to apparatus and methods (system) for limiting the movement between two objects to just two degrees of freedom of movement. <b>Object of the invention.</b> The Dual Axis V-Pivot is designed to limit the movement between two objects to just two degrees of freedom of movement and constrain the other four degrees of movement. <b>Background of operation.</b> A completely non constrained connection would allow all 6 degrees of freedom as follows: 1. Rotation about X axis (pitch) 2. Rotation around Y axis (roll) 3. Rotation around the Z axis (yaw) 4. Movement in the X direction 5. Movement in the Y direction 6. Movement in the Z direction The Dual Axis V-Pivot constrains the degrees of freedom of motion to any two of the follow degrees of freedom of motion 1. Rotation about the X axis (pitch) 2. Rotation about the Y axis (roll) 3. Rotation around the Z axis (yaw) <b>Background of prior art.</b> The closest device to this in operation is a universal joint (also commonly referred to as U joint, Cardan Joint, Hooke Joint or Hardy Spicer Joint). A universal joint typically consists of two pairs of bearings. Each pair is arranged at 90 degrees to the other pair. Each pair of bearings is supported in a yoke Each pair of bearings in each yoke is connected with an axle. These bearings can be plain bearings or ball or needle roller bearing assemblies. The two axles are connected at the centre to create a cross axle configuration. <b>Characteristics of existing universal joints. i) Each bearing will have a small amount of clearance. ii) There can be clearances between the stub axles and the inside diameter of the bearings. iii) Wear can cause these clearances to increase over time. iv) There can be clearances between the outside diameter of the bearings and the inner bearing surfaces of the yokes. v) These clearances contribute to imprecision of the desired constraints to and can allow movement in unwanted axis or directions. vi)The need to accommodate yoke assemblies (and in some cases ball bearing assemblies) make existing universal joints bulky. vii) Separate appendages or extensions of the assembly are required to mount each yoke to each object that is to be coupled, which can make traditional universal joints bulky. viii) Some method of assembly is required. The usual method is to press or fix the outer race of the bearings into each yoke. This is then fixed in place with circlips or staked in place, making assembly and disassembly difficult and or time consuming. iX) This can make coupling the two objects that are to pivot with respect to each other difficult and or time consuming. <b>Description of Invention.</b> The Dual Axis V-Pivot is a new and unique design of universal joint. It consists of: 1. Two axles joined in the centre in a cross configuration. Hereafter referred to as a crossaxle. The four ends of the crossaxle can be plain bearing surfaces (cylindrical or spherical as shown) or fitted with roller or needle bearings. Depictions of cross axles are shown in the accompanying images. 2. Two V blocks are orientated at 90 degrees to each other. Depictions of both discrete and integrated V-blocks are shown in the accompanying images. 3. Each bearing (or bearing surface) sits in a V-block, the V-blocks for each pair can be separate or a contiguous structure. The V-blocks form the yoke structures. 4. To allow the crossaxle assembly to rotate in two axis of freedom, clearance must be accommodated for in the yoke structure. This can be achieved in a number of ways including: i) using four individual V-blocks with space in between to allow the cross axle to rotate, ii) using contiguous V-blocks with a cut out in between the two bearings/bearing surfaces at each end of each axle to provide clearance for the other axle to rotate, iii) reducing the the cross section of the cross axle assembly between the the two bearings/bearing surfaces at each end of each axle to to provide clearance for the other axle to rotate, iv) some combination of items I), ii) and iii) above <b>Field of the invention:</b> The invention will be used to couple two objects together to constrain movement to just 2 axis of rotation between the devices coupled. An example of usage of the Dual Axis V bracket could be to provide the reference pivot in a 3D printer fitted with a 1P Z motion system. <b>The claims for the Dual Axis V-Pivot are as follows.</b> i) There will be no clearance between the outer surface of each axle (or bearing) and the V-block it sits in. ii) Wear will not cause clearance between the outer surface of each axle (or bearing) and the V-block it sits in. iii) Because the design minimizes or eliminates (in the case where the surfaces of the ends of each axle runs directly in the V-blocks) clearance between mating surfaces the precision of movement is maintained over the life of the assembly. v) Because the design minimizes or eliminates (in the case where the surfaces of the ends of each axle runs directly in the V-blocks) clearance between mating surface, there will be no movement in unwanted axis or directions over the life of the assembly vi)The V-blocks can be of slim design eliminating the need for bulky traditional yoke assemblies vii) The V-blocks can be integrated in to the items to be coupled. No separate appendages or extensions of the assembly are required to mount each yoke to each object that is to be coupled making the entire coupling assembly very compact. viii) Assembly is very simple. The cross-axle and the V-blocks need not be fixed to each other with any separate fixtures. The assembly can be held in place with a clamping force. In some applications gravity can provide the clamping force between the different parts of the assembly. ix) Without the need for separate fixings the coupling can be done extremely quickly and repetitively with out causing undue wear on components x) Because no separate fixings are required to assemble the coupling no tools or access for tools is required to mate the components.