The present invention relates to mechanical fastening of components, and more particularly to a retainer cage for blind-hole fastening of surface mounted components on a work vehicle.
Work vehicles used in the agricultural and construction industries typically have many surface mounted components attached at various locations on the work vehicle. Surface mounted components can include, for instance, structural parts such as frame components, operational parts such as a motor or hydraulic actuators, as well as vehicle body parts such as fenders and guards.
A surface mount typically involves one surface of a first component abutted against another surface of a second component. The components are then secured together, such as by fasteners. Often at least one fastener extends through aligned holes in both components. The surface mounted component to be added is referred to as the mounted component and the other component part is referred to as the supporting component or the support structure.
Surface mounted components are often assembled using a threaded male fastener such as a bolt that is configured to threadingly mate through the aligned holes with a threaded female fastener such as a nut. An assembler will usually hold either the bolt or the nut against rotation and torque the other of either the bolt or the nut to tighten the threaded fastener. The surface at which the assembler applies torque to the fastener will be referred to as the proximal surface and the surface at which the fastener is held against rotation will be referred to as the distal surface.
In some surface mounting situations, the female fastener must be aligned with the male fastener at a blind-hole. A blind-hole is the exit hole on a distal surface that is not readily seen or accessible by the assembler and through which the threaded end of the bolt protrudes. A blind hole can be on either the mounted component or on the supporting structure. In either situation, it may be difficult or impossible for an assembler to apply a tool to the nut for tightening or loosening the threaded fastener used to secure the surface mounted components.
Various assembly solutions have been used by assemblers to overcome the problem of restricted sight or access to the fastening nut on the distal surface. For example, a nut can be welded to the distal or blind side of the surface mounted component so that the assembler does not have to engage the nut with a tool during assembly. However, a nut that is permanently welded in place may not be suitable for some assembly situations since the fixed position of the nut does not allow for adjustments that may be needed due to the manufacturing tolerances of the components. For example, most fastener holes in both component parts are often separately pre-drilled prior to assembly.
Another technique for blind-hole fastening is to permanently attach a four-sided retainer cage containing a nut to the distal surface. The retainer cage with the pre-installed nut is often welded to the blind side of the appropriate surface mount component. The retainer cage allows some freedom of movement by the retained nut to compensate for adjustments needed due to the tolerances variations of the components.
However, because the retained nut is permanently installed in the fixed retainer cage, any concurrent or subsequent manufacturing or assembly procedures can damage the exposed female threads on the retained nut before mating with the male fastener. For example, if the component part with the retainer cage on the distal surface is painted, welded or sanded, the retained nut is subjected to weld spattering, paint or blasting media. These subsequent procedures require additional non-value added work to the exposed retained nut either before the subsequent procedures (such as masking the female threads on the nut) or after the subsequent procedures (such as re-tapping the threads). If there is substantial damage to the nut, either the retained nut or both the nut and the permanently affixed retainer cage may have to be removed and replaced.
Thus, there is a need for an open retainer cage that provides for the initial installation of a nut in the retainer cage after the retainer cage has been attached to the component part and only after any subsequent processes have been performed on the component part. There is a need for a retainer cage that can be utilized with currently existing assembly and manufacturing tooling. There is also a need for a retainer cage that allows for replacement of a damaged nut during the manufacturing process or during subsequent procedures such as maintenance.
According to the present invention, an open retainer cage for a nut type fastener includes a web with a first leg, a second leg and a third leg. All three legs are attached to the web and are configured to form a retainer cage with at least two of the legs in facing opposition to each other. The web can be provided with a tongue extending from the web over an area not occupied by one of the legs. The web and the three legs can be integrally formed from a single piece of material and the tongue can be integrally formed with the web. The tongue can bent or can be provided with a hole configured to receive a removable blocking member, which is used to confine a nut within the retainer cage.
There is also provided, in accord with the present invention, a retainer cage assembly for blind-hole mounting a component secured by threaded fasteners including a nut retained in an open retainer cage. The retainer cage includes a web with a first leg, a second leg and a third leg. All three legs are attached to the web and are configured to form a retainer cage with at least two of the legs in facing opposition to each other. The web can be provided with a tongue extending from the web over an area not occupied by one of the legs. The web and the three legs can be integrally formed from a single piece of material and the tongue can be integrally formed with the web. The tongue can be deformed or can be provided with a hole configured to receive a selectively insertable blocking member, which is used to confine a nut within the retainer cage.
There is also provided a method for retaining a nut type fastener including the steps of affixing an open retainer cage having a tongue portion to a surface. The nut is then inserted in the retainer cage. The nut can be confined in the retainer cage by installing a blocking member in a hole defined in a tongue portion of the retainer cage or by bending the tongue portion towards the surface thereby restricting the nut from movement out of the retainer cage.