32 34 that form the lower part of spring compartments walls between the grooves separate the grooves from one another the walls operate as end walls that the springs 70 bear against during use of the tensioner the grooves 32 34 are formed in a curved shape in the present instance the grooves follow an arc shaped curve in the present embodiment the second groove 34 is substantially a mirror of the first groove 32 additionally in the present instance the bottom surface of grooves 32 34 are rounded to correspond to the curvature of the convolutions of the springs 70 the cap 40 overlies the base 30 to enclose the springs 70 within the device additionally an elongated arm 15 is attached to the cap the arm 15 is configured to be connected with a machine element for instance in the present instance the arm 15 includes a mounting hole positioned remote from the cap 40 that can be used to attach a pulley 7 to the arm so that the tensioner can be used to tension a belt in the present instance the arm is integrally formed with the cap so that the arm and cap are a single piece however it may be desirable to form the arm and the cap separately so that the arm can be removably attached to the cap if desired the cap 40 is in the form of a generally cylindrically.