Abstract: A coned-disc spring device, spring assembly, methods of making the same, and methods of assembling a spring system are disclosed. Such a device includes a first end defining a first opening and a second end defining a second opening, wherein the diameter of the second opening is larger than the diameter of the first opening. The device also includes a lip portion at the second end of the device adjacent to and at least partially encircling the second opening and protruding substantially perpendicular to the plane defined by the second opening such that when a portion of a second spring member having a first groove portion is received within the second opening, the first lip portion is received within the first groove portion to optimally align the second spring member.

Abstract: A drawworks for a rig is disclosed. This drawworks may be used by any appropriate type of rig, such as a drilling rig or a service/workover rig. The drawworks includes at least one drum (e.g., a main drum, a sand drum), and each such drum may incorporate a number of desirable features. For instance, the drum may include a lubricant flowpath with at least one annular section that reduces the potential for clogging. This drum may also include a drive hub that is detachably interconnected with one or more drive sprockets so as to facilitate repair/replacement. Finally, this drum may include one or more structures for reducing the potential that certain lubricant will reach the clutch, where this lubricant is propelled from one or more rotating drive sprockets and/or the associated chain.

Abstract: An elastomeric polyurethane polymer arrow vane with a tapered fletch which will not wrinkle or warp when attached to an arrow shaft is described. The vane is prepared by injection molding in mold cavities with a reverse curve in the portion of the cavities which form the base of the vane which attaches to the arrow shaft so that the vane is straight or has a reverse curve after it is injection molded.

Abstract: A nonmetallic two-part vent particularly suitable for mounting upon the roof of recreational vehicles for the venting of appliances, particularly gas refrigerators. The vent includes a base having an integral screen formed of the base material and a cover is directly attached to the base overlying the screen.

Abstract: An elastomeric polyurethane polymer arrow vane with a tapered fletch which will not wrinkle or warp when attached to an arrow shaft is described. The vane is prepared by injection molding in mold cavities with a reverse curve in the portion of the cavities which form the base of the vane which attaches to the arrow shaft so that the vane is straight or has a reverse curve after it is injection molded.