tension in the upper and lower runs 19 and 21 of the drive element 18 moreover the tensioning device 10 would push the upper and lower runs 19 and 21 inwardly towards each other to remove the slack in the drive element 18 this arrangement maintains a greater surface area of the drive belt in contact with the outer surface of the sheaves 20 and 22 at any given time the tensioning device 10 may be similarly adjusted while remaining positioned on the outer surface of the drive element 18 to increase or decrease the tension of the drive element 18 to adjust the tension the v belt pulleys 16 a 16 d may be vertically repositioned within the housing 15 to either increase or decrease the distance between pulleys 16 a and 16 b and between pulleys 16 c and 16 d the pulley position may be adjusted by passing the fastener 28 through an aperture 24 either closer to or further away from the corner of the end plates 12 and 14 when the pulleys 16 a 16 d are repositioned further away from the corner of the end plates 12 and 14 the distance between pulleys 16 a and 16 b and between pulleys 16 c and 16 d is decreased and therefore the tension in the drive element 18 is increased.