Edge driven conveyor system

Claim 2

A conveyor system which comprises an endless flat conveyor belt supported in an endless path, friction drive means for said belt comprising an endless chain movable through an endless path having a run parallel to an edge of said belt a pluRality of frictional driving elements connected to said chain at spaced locations, said elements defining first frictional driving surfaces extending vertically and drivingly engaging said edge of the belt, and second frictional driving surfaces extending horizontally under said edge of the belt and drivingly engaging and supporting the bottom of said belt adjacent said edge, and power means for driving said endless chain to move said frictional driving elements in the same direction as and faster than the speed of said belt edge so that said first and second frictional driving surfaces slide along and frictionally drive said belt, means to urge said belt and said first frictional driving surfaces together to maintain the frictional driving engagement therebetween and positive drive means engaging said belt to drive said belt at a speed less than the speed of said frictional driving elements.

Claim 3

A conveyor system according to claim 1 wherein said endless path includes a straight run, said friction drive means engages said belt along said straight run, said means to urge said belt and said first frictional surfaces together includes means to apply a resilient force normal to said belt at said straight run to effect said urging together.

Claim 4

A conveyor system according to claim 1 wherein said belt is made up of a plurality of links collapsibly connected together to permit the belt to selectively bend edgewise within its own plane in either lateral direction, said endless path includes at least one lateral curve in the plane of the belt which requires the belt to bend edgewise in said plane as it enters and leaves said curve, and said friction drive means engages the inner edge of the belt along said curve.

Claim 5

A conveyor system according to claim 3 wherein said endless path includes a spiral in which said belt moves with a horizontal cross-section longitudinally through and bends edgewise within its own plane around a plurality of vertically spaced spiral loops with at least a portion of each of said loops being arcuate to define said curve, said frictional driving elements engaging said inner edge of the belt at said spaced locations substantially throughout said arcuate portions.

Claim 6

A conveyor system according to claim 4, wherein said spiral loops from equal coaxial circles to define a cylinder within said loops, and said friction drive means extends in driving relation with said belt continuously throughout substantially the entire length of said loops.

Claim 7

A conveyor system according to claim 5 wherein said endless path includes a pair of said spirals superimposed coaxially upon the same cylinder with the loops of the two spirals alternatingly spaced between each other, said belt and said friction drive means passing upwardly in one circumferential direction along one of said spirals, turning around at the top of said spirals and passing downwardly in the opposite circumferential direction along the other of said spirals, said belt having the same conveying surface facing upwardly throughout said passing upwardly, turning around and passing downwardly, one edge of the belt defining said inner edge during said passing upwardly and the other edge of the belt defining said inner edge during said passing downwardly, and further comprising means to transfer said friction drive means from said one edge to said other edge at the top of said spirals.

Claim 8

A conveyor system according to claim 4, wherein said spiral loops are horizontally elongated with said arcuate portions at the ends of the elongated loops and with straight portions extending tangentially between said arcuate portions.

Claim 9

A conveyor system according to claim 7, wherein said endless path includes a pair of said spirals in vertical alignment with the loops of the two spirals alternating spaced between each other, said belt passing upwardly in one circumferential direction along one of said spirals, turning around at the top of said spirals and passing downwardly in the opposite circumferentiAl direction along the other of said spirals, said belt having the same conveying surface facing upwardly throughout said passing upwardly, turning around and passing downwardly, one edge of the belt defining said inner edge during said passing upwardly and the other edge of the belt defining said inner edge during said passing downwardly.

Claim 10

A conveyor system which comprises an endless flat conveyor belt, a positive drive means operable at a predetermined speed and engaging said belt to drive said belt at said predetermined speed, said belt being supported in an endless path of such length that the force required to move the belt through said path exceeds the capacity of said positive drive means, and at least one supplemental friction drive means comprising an endless chain movable through an endless path having a run parallel to an edge of said belt, a plurality of frictional driving elements connected to said chain at spaced locations, said elements defining first frictional driving surfaces extending vertically and drivingly engaging said edge of the belt, and second frictional driving surfaces extending horizontally under said edge of the belt and drivingly engaging and supporting the bottom of said belt adjacent said edge, and power means for driving said endless chain to move said frictional driving elements in the same direction as and faster than the speed of said belt edge so that said first and second frictional driving surfaces slide along and frictionally drive said belt to maintain the tension of said belt at said positive drive means and at said friction drive means within the capacities of said respective drive means.

Claim 11

A conveyor system which comprises an endless flat conveyor belt, a positive drive means operable at a predetermined speed and engaging said belt to drive said belt at said predetermined speed, said belt being supported in an endless path of such length that the force required to move the belt through said path exceeds the capacity of said positive drive means, and at least one supplemental friction drive means comprising an endless chain movable through an endless path having a run parallel to an edge of said belt, a plurality of frictional driving elements connected to said chain at spaced locations, said elements defining first frictional driving surfaces extending vertically and drivingly engaging said edge of the belt, and second frictional driving surfaces extending horizontally under said edge of the belt and drivingly engaging and supporting the bottom of said belt adjacent said edge, and power means for driving said endless chain to move said frictional driving elements in the same direction as and faster than the speed of said belt edge so that said first and second frictional driving surfaces slide along and frictionally drive said belt to maintain the tension of said belt at said positive drive means and at said friction drive means within the capacities of said respective drive means.

Claim 12

A conveyor system according to claim 9, wherein said endless belt path includes a run aligned, around a curve in the plane of said belt, said frictional driving elements engaging the inner edge of said belt around said curve.

Claim 13

A conveyor system according to claim 10, wherein said conveyor belt comprises a plurality of links collapsibly connected together to permit the belt to selectively bend edgewise within its own plane in either lateral direction and said endless belt path includes runs leading to and away from said curve requiring said belt to bend edgewise as it enters and leaves said curve.

Claim 14

A conveyor system according to claim 9, wherein said endless belt path includes a straight run, said frictional driving elements engaging an edge of said belt along said straight run, there being provided means along said straight run to urge said belt and said endless chain against each other to maintain the engagement between said belt and said frictional driving elements.

Claim 15

A conveyor system according to claim 12, wherein another of said supplemental friction drive means is located adjacent and in frictional driving relation with the other edge of the belt along said straight run.

Claim 16

A conveyor system according to claim 9, including an end pulley around which said belt is moved to provide vertically spaced and aligned aligned aligned parallel runs with said belt moving in opposite directions therein, wherein said endless chain has aligned parallel oppositely moving runs corresponding to the parallel runs of said belt with said frictional driving elements engaging an edge of said belt along each of said parallel runs of the belt.

Claim 17

A conveyor system according to claim 9 comprising a plurality of said supplemental friction drive means disposed at spaced locations along the path of said belt.

Claim 18

A conveyor system which comprises an endless flat conveyor belt made up of a plurality of links collapsibly connected together to permit the belt to selectively bend edgewise within its own plane in either lateral direction, said belt being supported in an endless path including a plurality of straight runs and a plurality of curved runs in which the belt bends edgewise, positive drive means operable at a predetermined speed and engaging said belt to drive said belt at said predetErmined speed, said positive drive means having insufficient capacity to supply the total driving force to move said belt through said path, and a plurality of supplemental friction drive means engaging said belt at spaced locations along said path to maintain the tension of said belt at said positive drive means and at each of said friction drive means within the capacities of said respective drive means, each of said friction drive means comprising an endless chain movable through an endless path having a run parallel to an edge of said belt, a plurality of frictional driving elements connected to said chain at spaced locations, said elements defining first frictional driving surfaces extending vertically and drivingly engaging said edge of the belt, and second frictional driving surfaces extending horizontally under said edge of the belt and drivingly engaging and supporting the bottom of said belt adjacent said edge, and power means for driving said endless chain to move said frictional driving elements in the same direction as and faster than the speed of said belt so that said first and second frictional driving surfaces slide along and frictionally drive said belt, said supplemental friction drive means being located to engage said belt at a respective curved run along the inner edge thereof, and at a respective straight run at one of the edges thereof with means being located at said respective straight run to urge the belt and the endless chain toward each other to maintain the frictional engagement between the belt and the frictional driving elements.

Claim 19

A conveyor system which comprises an endless flat conveyor belt made up of a plurality of links collapsibly connected together to permit the belt to selectively bend edgewise within its own plane in either lateral direction, said belt being supported in an endless path including a plurality of straight runs and a plurality of curved runs in which the belt bends edgewise, positive drive means operable at a predetermined speed and engaging said belt to drive said belt at said predetErmined speed, said positive drive means having insufficient capacity to supply the total driving force to move said belt through said path, and a plurality of supplemental friction drive means engaging said belt at spaced locations along said path to maintain the tension of said belt at said positive drive means and at each of said friction drive means within the capacities of said respective drive means, each of said friction drive means comprising an endless chain movable through an endless path having a run parallel to an edge of said belt, a plurality of frictional driving elements connected to said chain at spaced locations, said elements defining first frictional driving surfaces extending vertically and drivingly engaging said edge of the belt, and second frictional driving surfaces extending horizontally under said edge of the belt and drivingly engaging and supporting the bottom of said belt adjacent said edge, and power means for driving said endless chain to move said frictional driving elements in the same direction as and faster than the speed of said belt so that said first and second frictional driving surfaces slide along and frictionally drive said belt, said supplemental friction drive means being located to engage said belt at a respective curved run along the inner edge thereof, and at a respective straight run at one of the edges thereof with means being located at said respective straight run to urge the belt and the endless chain toward each other to maintain the frictional engagement between the belt and the frictional driving elements.

Claim 20

A conveyor system according to claim 16, wherein said supplemental friction drive means are located at opposed positions on both sides of the belt along said respective straight run.

Claim 21

A conveyor system which comprises an endless flat conveyor belt made up of a plurality of links collapsibly connected together to permit the belt to bend selectively edgewise within its own plane, and a belt supporting and driving assembly comprising a support rail to support said belt with a substantially horizontal cross-section in an endless path extending longitudinally and curving edgewise in its own plane through a spiral having a plurality of vertically spaced loops defining a cylinder, said rail engaging the bottom of the belt near the outer edge thereof substantially throughout the length of said loops, frictional drive means for moving said belt through said spiral, said frictional drive means comprising an endless chain extending parallel to said inner edge of said belt and having connected thereto at spaced locations a plurality of vertical frictional driving elements engaging said inner edge in sliding frictional driving relation substantially throughout the length of said loops and a plurality of horizontal frictional driving and supporting elements extending under said inner edge in frictional driving and supporting engagement with the bottom of said belt adjacent said inner edge substantially throughout the length of said loops, and power means for driving said chain, and positive driving means engaging said belt to drive said belt at a predetermined speed, said power means for driving said chain being operative to move said frictional driving elemenets at a faster rate than said inner belt edge when said belt is moving at said predetermined speed.

Claim 22

A conveyor system which comprises an endless flat conveyor belt made up of a plurality of links collapsibly connected together to permit the belt to bend selectively edgewise within its own plane, and a belt supporting and driving assembly comprising a support rail to support said belt with a substantially horizontal cross-section in an endless path extending longitudinally and curving edgewise in its own plane through a spiral having a plurality of vertically spaced loops defining a cylinder, said rail engaging the bottom of the belt near the outer edge thereof substantially throughout the length of said loops, frictional drive means for moving said belt through said spiral, said frictional drive means comprising an endless chain extending parallel to said inner edge of said belt and having connected thereto at spaced locations a plurality of vertical frictional driving elements engaging said inner edge in sliding frictional driving relation substantially throughout the length of said loops and a plurality of horizontal frictional driving and supporting elements extending under said inner edge in frictional driving and supporting engagement with the bottom of said belt adjacent said inner edge substantially throughout the length of said loops, and power means for driving said chain, and positive driving means engaging said belt to drive said belt at a predetermined speed, said power means for driving said chain being operative to move said frictional driving elemenets at a faster rate than said inner belt edge when said belt is moving at said predetermined speed.

Claim 23

A conveyor system according to claim 18, wherein said belt is supported in a second spiral superimposed upon said cylinder with the loops of said second spiral defining circles equal and coaxial with the circles of the first named spiral and alternatingly spaced therebetween, said belt and said friction drive means passing upwardly in one circumferential direction along one of said spirals, turning around at the top of said spirals and passing downwardly in the opposite circumferential direction along the other of said spirals, said belt having the same conveying surface facing upwardly throughout said passing upwarDly, turning around and passing downwardly, one edge of the belt defining said inner edge during said passing upwardly and the other edge of the belt defining said inner edge during said passing downwardly, and further comprising means to transfer said friction drive means from said one edge to said other edge at the top of said spirals.