Patent ID: 8123025

Claim:
A turnaround curve system for a compact chain conveyor system having minimal oscillation due to speed fluctuations, comprising a chain having linear traction which is driven through turnaround sections by means of passive turnaround guides, wherein the turnaround guides define a guide path obtained by appending a family of curves corresponding to paths defined by six points, said six points corresponding to six linkage positions of consecutive links of the chain in the turnaround sections, such that: a first path between the first point and the second point and a fifth path between the fifth point and the sixth point define a constant linear speed parallel to a straight section of the chain between the turnaround sections; a second path is between the second point and the third point and the fourth path is between the fourth point and the fifth point; a third path is between the second and fourth path; wherein each path is of substantially the same length wherein when each linkage passes to a position occupied by the previous linkage in a time interval “t”, the paths are defined by six points determined by the following equations: X 1=− P; Y 1= H/ 2; X 2=0; Y 2= H/ 2; X 3= P *cos( b ); Y 3= P/ 2; X 4= P *cos( b ); Y 4=− P/ 2; X 5=0; Y 5=− H/ 2; X 6=− P; Y 6=− H/ 2; where: P: chain pitch value; H: distance between a first branch and a second branch of the chain; b=a sin((H/2−P/2)/P) wherein the curves of the paths are further defined by the following equations: X 1( t )=− P+P*t; Y 1( t )= H/ 2; 1-2: ( X 2− X 1)^2+( Y 2− Y 1)^2= P^ 2; X 2/( Y 2+ D )=tan( a )* t ; where a=a tan( P *cos( b )/( P/ 2 +D )); 2-3≡f1(D): ( X 3− X 2)^2+( Y 3− Y 2)^2= P^ 2; ( X 3− X 4)^2+( Y 3− Y 4)^2= P^ 2; 3-4: t′= 1− t X 4( t ′)= X 2( t ); Y 4( t ′)=− Y 2( t ); 4-5: X 5( t )=− P*t; Y 5( t )=− H/ 2; 5-6: assigning to “t” a value comprised between 0 and 1, selecting a set value for either P or H and iteratively varying D until the following condition is met: dX 2/ dY 2( t= 1)= dX 3/ dY 3( t= 0) dX 3/ dY 3( t= 1)= dX 4/ dY 4( t= 0) the geometry of the guide is defined by the rolling path of the roller when the linkages follow the defined paths.