Abstract:
An awning is attached to and wound on a spring loaded roller. The roller rotates on shafts secured to shaft mounts at each end. The shaft mount is secured on the end of a support arm. A crank has a two prong engagement member that fits in a slot of the shaft mount. The shaft mount is released from the support arm and the crank is turned to adjust spring force in the roller.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of awnings and specifically to a system for adjusting force of a spring loaded awning roller. 
     Awnings for buildings and vehicles are often wound on a spring loaded roller. The spring maintains tension on the awning and facilitates retraction or deployment of the awning. As the spring ages, its force may decrease. In some cases, a change in the awning or its installation may result in the spring force being excessive or inadequate. It is, therefore, desirable to adjust the force of the spring. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a roller crank system including a crank having an arm, a handle, and a first engagement member. A roller is rotatably mounted on a shaft. A shaft mount is connected for rotation with the shaft and has a second engagement member for receiving the first engagement member. The first engagement member is a pair of parallel prongs. The second engagement member is a slot. The handle, arm, and one of the prongs are formed from a single bar bent at two substantially right angles to define an S shape. A spacer is provided for spacing the second prong from and securing the second prong to the first prong. 
     A support arm supports the shaft and is releasably secured to the shaft mount. The support arm has a notch corresponding with the second engagement member. The shaft mount is partly nested in the support arm such that a part of the second engagement member is nested in the support arm. The support arm has an open notch corresponding with the second engagement member and permits release of the shaft support from the support arm when the first engagement member is engaged with the second engagement member. When the second engagement member is a slot, the notch permits passage of the first engagement member into the slot. The support arm is pivotably secured to a wall. 
     A spring urging rotation of the roller relative to the shaft. A lock selectively prevents rotation of the roller on the shaft. The lock prevents rotation of the roller in one direction while permitting rotation of the roller in another direction. 
     The invention also provides a method of adjusting spring force in a spring loaded roller mounted for rotation on a shaft, the shaft being engaged with a shaft mount having an engagement member and supported by a support arm. The method includes the steps of engaging a crank with the shaft mount engagement member; releasing the shaft mount from the support arm; turning the crank to adjust the force of the spring; replacing the shaft mount on the support arm; securing the shaft mount to the support arm; and disengaging the crank from the shaft mount. The invention also includes the step of setting a roller lock in a position permitting rotation of the shaft in a direction necessary to adjust the force of the spring prior to turning the crank. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 shows a perspective view of an awning assembly according to the invention; 
     FIG. 2 shows a view of a roller and shaft mount in a section taken from line  2 — 2  of FIG. 4; 
     FIG. 3 shows a front view of the roller and shaft mount in a section taken from line  3 — 3  of FIG. 4; and 
     FIG. 4 shows an isometric view of an end of the roller and the shaft mount. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a recreational vehicle  10  includes a side wall  12  having an awning assembly  14  mounted thereon. An awning rail  16  is fastened along an upper part of the wall  12 . An edge of an awning canopy  18  is secured to the awning rail  16 . An opposite edge of the awning  18  is secured to a roller  20 . The roller is supported by a pair of support arms  22  removably mounted to the wall  12 . Retractable rafters  24  maintain tension on the awning  18 . 
     Referring to FIG. 2, the roller  20  includes a hollow tube  30  provided with an end cap  32  at each end and idler bearings  34  near each end. A roller shaft is defined by torsion rods  36  supported by the respective end caps  32  and idler bearings  34 . A spring, such as a torsion spring  38  wound around each torsion rod  36 , urges rotation of the roller  20  relative to the torsion rods  36 . A roller lock  40  having an operating lever  42  is provided at one end of the roller  20 . The lock  40  preferably includes one member mounted to the roller  20  and another member mounted to the shaft. In one locking position (“ROLL DOWN”), the lock  40  prevents rotation of the roller  20  in a first direction while permitting rotation in a second direction. In another locking position (“ROLL UP”), the lock  40  prevents rotation of the roller  20  in the second direction while permitting rotation in the first direction. 
     Referring to FIGS. 2 and 3, the torsion rods  36  are supported on upper ends of the respective support arms  22 . The rod  36  is retained on the support arm  22  by a shaft mount, such as a top casting  44 . The rod  36  extends through a wall of the casting  44 . A pin  46  through the torsion rod  36  is received in recesses  48  or holes in the top casting  44  to prevent rotation of the rod relative to the casting  44 . An engagement member, such as a crank slot  50 , is provided at a wall of the top casting  44  opposite the roller  20 . Preferably, the slot  50  is closed. The top casting  44  is partly nested in the support arm  22  such that a shoulder  51  of the casting  44  rests on an upper edge of the support arm  22 . A lower part of the slot  50  is disposed within the support arm  22 . An notch  52  is provided in the support arm  22  that corresponds with the part of the slot  50  within the support arm  22 . The top casting  44  is retained on the support arm  22  by a bolt  54 . 
     Referring to FIG. 4, a crank  56  includes a handle  58 , an arm  60 , an engagement member, such as a pair of prongs  62 , and a spacer  64  between the prongs  62 . Preferably, the handle, arm, and one of the prongs are formed from a single piece of bar stock having a circular or octagonal cross-section and bent at right angles to provide a distinctive appearance. The other prong is made of similar material. The spacer  64  is welded to the one prong and the other prong is welded to the spacer  64  so that the prongs  62  are parallel and spaced apart. Preferably, the crank  56  is formed from a 0.31 inch (0.79 cm) diameter steel rod having a length of about 14.0 inches (35.6 cm). The second prong is a 0.31 inch (0.79 cm) diameter steel rod having a length of about 4.0 inches (10.2 cm). The handle  58  is about 5.0 inches (12.7 cm) long and the arm  60  is about 5.0 inches (12.7 cm) long. The bends defining the handle, arm, and prong parts of the crank  56  have about a 0.62 inch (1.57 cm) bend radius. The spacer  64  is a {fraction (5/16)} inch (0.79 cm) by ½ inch (1.27 cm) steel bar about 1.0 inch (2.5 cm) long. The spacer  64  is welded between the prongs  62  so that the prongs  62  project about 2.0 (5.1 cm) inches from the spacer  64 . 
     In operation, the prongs  62  are inserted in the slot  50 . Typically, the roller lock  40  is provided at only one end of the roller  20 . If the spring  38  at the locked end is being adjusted, the lock  40  must be in the proper position. To increase the force of the spring  38 , the lever  42  is placed in the “ROLL DOWN” position. To reduce the force of the spring  38 , the lever  42  is place in the “ROLL UP” position. 
     The bolt  54  is removed from the support arm  22  to release the top casting  44 , which is then removed from the support arm  22 . The crank  56 , and therefore the casting  44  and rod  36 , are rotated until the spring  38  has the desired force. The  56  crank transmits a torsional force that alters the tension or compression of the spring  38 . Indicia, such as arrows, can be provided to indicate the direction of rotation for adding or removing force. The casting  44  is replaced on the support arm  22 . 
     The present disclosure describes several embodiments of the invention, however, the invention is not limited to these embodiments. Other variations are contemplated to be within the spirit and scope of the invention and appended claims.