# US 2014/0151182 A1 · Idler roller conveyor system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151182 A1 - Document ID: US20140151182A1 - Status: Published application - Kind: A1 - Application number: 14/088,672 - Filed: 2013-11-25 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Inventors: Raymond Edward Poehlein; Daniel Patrick Poehlein - Web page: https://patentgrep.com/patent/US20140151182A1 ## CPC - B65G 13/12: adjustable - B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D) ## Abstract An idler roller conveyor uses paired rollers set at an acute angle to each other with the rollers being coplanar and skewed toward opposite sides of a perpendicular to a longitudinal axis of the conveyor. Roller pairs are preferably mounted in sub-frames that pivot about on an axis transverse to the conveyor's longitudinal axis. This arrangement produces opposing transverse forces that are subtractive to result in negligible resultant transverse forces that are unlikely to make an object veer off course. ## Claims ### Claim 1 A conveyor system having a longitudinal axis oriented in an intended direction of travel of a transported object, and idler rollers being mounted to cross the longitudinal axis, the system comprising: any number of pairs of idler rollers having axes that are coplanar, non-parallel, acutely angled to each other, and are skewed toward opposite sides of a perpendicular of the longitudinal axis; and a conveyor whose longitudinal axis needs only to be aligned, with respect to the intended direction of travel, to within +/−½ of the acute angle between the skewed rollers. ### Claim 2 (depends on 1) The system of claim 1 wherein the opposed skewing of the paired roller axes in roller pairs causes transverse forces between an object and each of the paired rollers to be subtractive to minimize resultant transverse forces acting upon the transported object. ### Claim 3 (depends on 1) The system of claim 1 wherein transverse forces on an object engaging the paired rollers urge the object in different directions which are subtractive. ### Claim 4 (depends on 1) The system of claim 1 wherein the pair of rollers are mounted to be pivotable on an axis transverse to the longitudinal axis. ### Claim 5 (depends on 1) The system of claim 1 wherein the resultant transverse forces between the roller pairs and an object moving along the conveyor can be expressed: TF = Fn   μ  [ Cos  ( Θ + δ ) - Cos  ( Θ - δ ) ] 2 wherein Fn is the total normal force between the object and the roller pair; μ is the coefficient of friction between the surfaces of the rollers and the object; Θ is the misalignment angle between the conveyor's longitudinal axis and the intended feed transport direction; and δ is the skew angle between each roller of the roller pair and a perpendicular to the conveyor longitudinal axis. ### Claim 6 A method of reducing resultant transverse forces occurring between idler rollers of a conveyor and an object moving along the conveyor in an intended direction, the method comprising: mounting a pair of the rollers to extend across the intended direction so that the rollers are coplanar, non-parallel, and are acutely angled relative to each other; and disposing axes of the paired rollers on opposite sides of a perpendicular to the intended direction so that the transverse force between the object and one of the paired rollers is directionally opposite to the transverse force between the object and another one of the paired rollers. ### Claim 7 (depends on 6) The method of claim 6 including mounting the roller pair so that a bisector of the acute angle between the rollers is approximately perpendicular to the intended direction. ### Claim 8 (depends on 6) The method of claim 6 including mounting the rollers in a pivotal sub-frame that extends across the intended direction and allows the roller pair to pivot evenly into engagement with the object. ### Claim 9 (depends on 6) The method of claim 6 including mounting the paired rollers in a frame oriented generally in the intended direction so that the paired rollers interact with the object to produce transverse forces in opposite directions. ### Claim 10 (depends on 6) The method of claim 6 wherein resultant transverse forces between the conveyor and an object moving along the conveyor are expressed as: TF = Fn   μ  [ Cos  ( Θ + δ ) - Cos  ( Θ - δ ) ] 2 wherein Fn is the total normal force between the object and the roller pair; μ is the coefficient of friction between the surfaces of the rollers and the object; Θ is the misalignment angle between the conveyor's longitudinal axis and the intended feed transport direction; and δ is the skew angle between each roller of the roller pair and a perpendicular to the conveyor longitudinal axis. ### Claim 11 (depends on 6) The method of claim 6 wherein any departure of the intended direction of travel from a longitudinal axis of the conveyor is limited to plus or minus ½ the acute angle between the skewed rollers. ### Claim 12 In a conveyor having a frame with a longitudinal axis and mounting a plurality of idler rollers, the improvement comprising: the rollers being arranged in pairs having axes that are coplanar, non-parallel, and acutely angled from each other; the paired roller axes being deployed at skew angles δ on opposite sides of a perpendicular to the longitudinal axis; the rollers being arranged in a pivotal sub-frame that extends across the longitudinal axis and allows the roller pair to pivot evenly into engagement with the object; the conveyor being subject to resultant transverse forces TF between the paired rollers and an object moving over the paired rollers, resulting in: TF = Fn   μ  [ Cos  ( Θ + δ ) - Cos  ( Θ - δ ) ] 2 wherein Fn is the total normal force between the object and the roller pair; μ is the coefficient of friction between the surfaces of the rollers and the object; Θ is the misalignment angle between the conveyor's longitudinal axis and the intended feed transport direction; and δ is the skew angle between each roller of the roller pair and a perpendicular to the conveyor longitudinal axis. ### Claim 13 (depends on 12) The improvement of claim 12 wherein any misalignment between the intended direction of travel and the longitudinal axis is held within plus or minus ½ the acute angle between the skewed rollers.