Patent Application
20050036852
1 . Field of the Invention
The present invention relates to fasteners and more particularly to a modified two-piece fastener with key way and locking piece for use in a spike, screw or nail system for providing improved holding ability when subjected to regular and/or extreme vibrations or stresses.
2. Description of the Prior Art
Railroad spikes, railroad screw spikes, bridge spikes, and other nails are well known within their respective industries. The general function of these various devices is to firmly hold different mediums together. Railroad spikes are used to hold steel rails and tie plates against wooden railroad ties; railroad screw spikes are used to hold steel rails and tie plates to railroad ties at intersections; longer anchor screws or spikes are used to hold multiple railroad ties together; bridge spikes are used to hold wooden piers or bridge tresles together; and nails are used for unlimited connective purposes.
In the example of the railroad spike, trains passing over a spike cause heavy vibrations with repeated compression and decompression of the rails and ties, which eventually loosens the spike, rails, tie plates and/or ties. This can cause widening of the rail gauge resulting in the derailment of a passing train. Train derailments are serious and may result in damage to railroad assets, with the loss of property and freight, including but not limited to, the release of hazardous materials, and the potential loss of human life. In an attempt to prevent the possibility of disastrous derailments or accidents from unstable tracks, railroad companies expend enormous amounts of time, money and resources in on-going inspections, resulting in replacing or attempting to tighten the spikes.
Similarly, wooden bridges, piers and docks are held together with specially designed spikes. Over time, changes in weather, temperature, pressure, as well as constant use and buffeting also result in the loosening of these spikes from the medium, causing the bridge, pier, dock or other structure to become unstable. In fact, in almost any connective situation involving a spike, screw or nail, over time the various stresses and pressures applied to the connected mediums can result in the loosening and diminishment of the connection.
A variety of devices have been invented attempting to address these problems:
U.S. Pat. No. 82,900 discloses a spike and key combination. The spike contains an inclined or curved hole from one side of the spike to the other, with a vertical guide-groove along one side from the head of the spike to the hole upon that side. The spike is driven into the medium. The key is then also driven directly into the medium against the guide-groove of the spike. While within the medium, the key enters the spike through the inclined hole and exits at an angle through the other side, forming a locking mechanism within the medium.
U.S. Pat. No. 971,308 discloses a slightly curved spike utilizing upwardly and outwardly inclined teeth along the sides of the spike. The teeth provide a hooking feature that makes the spike difficult to dislodge once it is inserted into the medium. The slight curvature of the spike provides additional placement support for the teeth by grasping the walls of the hole when the spike is subject to heavy vibrations.
U.S. Patent No. 5,429,300, also by the inventor of the present invention, discloses another spike and key combination. The spike contains a vertical groove cut into one side, extending from the spike head down to approximately one third the length of the shaft, and tapered at the lower end in an outwardly direction. The spike is driven into the medium. The key is then driven down the vertical groove within the spike, and bent outward by the lower end taper to form a locking mechanism.
However, each of these inventions has its drawbacks. For example, the diameter of the hole created by inserting a U.S. Pat. No. 971,308 spike into a medium equals the diameter of the spike itself. Though the slight curvature and angled teeth allows the spike to grip the walls of the hole, constant heavy vibrations will cause the spike to move in all directions and ultimately force it to dislodge its grip. The other inventions, utilizing angularly directed keys within the medium, fare little better; the vibrations and omnidirectional movement of the spikes and keys will ultimately cause the keys to dislodge from the spike hole or groove.
The curvature of the U.S. Pat. No. 971,308 spike presents an additional problem, in that such curvature increases the difficulty of driving the spike into the medium. Specifically, the force necessary to drive the spike into the medium must be exerted directly downward. However, the curvature of the spike deflects the force in the concave direction, possibly causing the spike to slip to the opposite direction and resulting in injury.
Additional problems exist with the U.S. Pat. No. 82,900 spike and key. First, the key is driven separately into the medium along an external vertical groove. The key may not be aligned properly to the angular hole within the spike, causing the key to miss the hole entirely and thus negating any angular support for the spike within the medium. Since the alignment occurs within the medium, it is difficult to determine whether the spike and key are properly aligned. Furthermore, the angular hole traverses the entire width of the spike. This particular design weakens the structural integrity of the spike, and increases the likelihood that heavy vibrations will cause the spike to bend or break within the medium at that particular width.
It is therefore the most important object of the present invention to provide an improved two-piece fastener, spike, screw or nail system having a key way and locking piece that provides substantial connective stability when installed into wooden ties or other similar media. The invention is a safety device that helps prevent rail rollover, wide gauge, loose spikes, and which solves other various problems within the railroad industry.
It is another important object of the present invention to provide a two-piece fastener, spike, screw or nail system including a first shaft that provides significant downward connection from the shaft of a fastener, spike, screw or nail; beveled/countersink chamfers for greater alignment; and improved connective and stabilizing characteristics associated with a second shaft having frictional joining wedges.
It is another important object of the present invention to provide a two-piece fastener, spike, screw or nail system that is not easily dislodged when subject to heavy vibrations, lateral forces, rail rollover, weathering effects, hot/cold temperatures, repeated rail compression/decompression caused by expansion/contraction of the rails and wooden ties of said medium as trains pass over, thereby avoiding widening of the rail gauge which can otherwise result in the derailment of a passing train.
It is a further object of the present invention to provide a three-piece fastener system for holding media together that includes a first piece made up of a shaft member with a head designed to be driven into a medium, the head having a chamfered opening leading into a key way which extends part way down one side of the shaft and has an outward taper towards the bottom; a second piece in the form of a smaller shaft having at least one frictional wedge along one or more sides for cutting into the key way and frictionally connecting with the first piece such that the smaller shaft extends out from the first shaft and into the medium when fully driven into the key way; and a third optional piece in the form of a plate member having an opening with the same cross section as the first shaft for receiving this shaft and thereafter becoming frictionally attached to it through the driving of the second shaft into the key way.
The present invention satisfies these objectives by providing a main fastener in the form of a spike, screw or nail having a shaft with a round, square or rectangular cross section, a point at one end and a head at the opposite end. A vertical slot or groove (“key way”) is provided along part of one side of the shaft leading to an opening at the head. The opening at the head includes one or more beveled/countersink chamfers that help center and align a second shaft in the form of a directional key that fits into the key way.
The key way is open at the top (i.e. on the head) of the fastener, spike, screw, or nail and extends downward along an outside edge of the shaft for a pre-determined distance, depending on the length of the shaft and the medium into which it is expected to be driven. An exemplary distance for the key way may be approximately one third the length of the shaft of the fastener, spike, screw or nail. The bottom edge of the key way has an outward taper. The cross sectional shape of the key way may be slightly to severely rectangular, oval, elliptical, or the like, but it could be round or square. The key way preferably has a shape that provides directional orientation to the second piece of the invention that fits into the key way. It is to be appreciated that a round or square shape may not provide this orientation.
The second piece of the invention is a separate directional nail or shaft (“key”) that fits into the key way. The key may be provided having any of a number of different cross-sectional shapes, so long as the shape corresponds to that of the key way in the main shaft. It is preferred that the key and key way have a rectangular cross section, but they may alternatively be oval, elliptical, or the like. Such shapes make the key directional, so that it only fits into the key way when properly oriented. The key is longer than the key way so that as it is driven into the key way, the bottom portion is bent out by the bottom tapered edge of the key way, so that it protrudes out into the medium into which the main shaft has been driven. The key includes at least one, although preferably a pair, of raised areas (“friction wedges”) which, when driven (hammered) into the shaft, cut one or more grooves into the key way causing a wedging effect which has dynamic holding ability. The friction wedges can be of any suitable shape, size and number, and can be placed in any location on the area of the key that comes into contact with the key way. The wedges are preferably provided in the form of a pair of elongated ridges located on opposite sides of the key, extending down a short distance below the head of the key. The friction wedges are positioned so that when the key is properly oriented into the key way, the friction wedges make contact with the sides of the key way. The relatively short length of the friction wedges allows most of the body of the key to be more easily driven into the key way before the friction wedges which require more force. As the final section of the key, including the friction wedges, is driven into the key way the wedges cut grooves into the key way that lock the key into place.
The head of the key is large (although not as large as the head of the main spike) for driving and removal purposes. The key head may be shaped so that it fits flush into the chamfered edge of the key way opening of the main spike. However, it is preferred that the key head be provided with one or more stops which when driven into the key way, make contact with the head of the main fastener, spike, screw or nail of the system. In this preferred configuration, the stops are located underneath and on opposite sides of the head of the key, and one or more tapered areas are provided on the sides, preferably at right angles to the stops. The tapered areas slope downward from the underside of the head to the top of the friction wedges. The stops prevent the head from being driven flush against the head of the main spike. The tapered areas leave openings on either side of the key head that allow for the insertion of manual or automated tools for easy removal of the key from the key way.
The key is preferably tapered at the bottom in conformity with the taper in the key way itself. The downward driving process of the key into the key way causes grooves to be cut into the sides of the key way by the friction wedges, and causes the lower portion of the key to bend and project outward at the bottom taper of the key way, away from the main spike or shaft and into the wooden tie or other medium into which the main shaft of the fastener, spike, screw or nail system has already been firmly installed. This angled insertion into the wooden tie or other medium provides greater stability to the main spike or shaft of the fastener, spike, screw or nail system, since it provides more than just the downward angle of connection that the main spike or shaft of the fastener, spike, screw or nail system would otherwise provide.
Provided at the bottom of the key shaft, are tapers which are located on both sides of the key, opposite to the sides having the friction wedges. The tapers preferably angle downward to a blunt end opposite the head. The blunt end is designed to cut fibers while being driven into a wooden cross tie or other appropriate medium. The blunt end of the key may also be used as a tool to clear the key way, which is accomplished by driving a key downward into the key way.
The spike or shaft of the main fastener, spike, screw or nail system is first driven into the tie or selected medium. Once it is firmly in place, the directional key is oriented and then inserted into the key way and driven downward, such that the friction wedges on the key self-cut along the sides of the key way, which creates a stronger wedging effect that withstands heavy pressures and vibrations. This driving process causes the lower portion of the key to be bent outward at an angle away from the main spike or shaft of the fastener, spike, screw or nail system and into the medium into which the main spike or shaft of the spike, nail or screw system has already been installed. This angled insertion into the medium provides greater stability to the main spike or shaft, since it provides more than just the downward taper of connection that the main spike or shaft would otherwise provide. Furthermore, when the fastener, spike, screw or nail system of the present invention is installed, strong vibrations or weathering is less likely to dislodge the key, due to the metallic binding from the grooves made in the key way by the self-cutting of the friction wedges. This creates strong, long-lasting holding ability, which locks and holds the key in place thus restricting the ability of the key to become dislodged from the key way.
Once the key is completely driven into the key way, the stops on the head of the key make contact with the top of the head of the main spike or shaft. This leaves the tapered areas on the sides of the key head of the key exposed for easy removal of the key from the key way either manually or by automated equipment.
In an alternative embodiment, a metallic member such as a tie plate is also provided with or on the medium. A typical railroad tie plate supports the rails and provides an interface between the rails above and the wooden tie below. The tie plate includes a plurality of openings through which the first large shafts or spikes of the present invention may be driven. Then, when the smaller shaft is driven into the key way of such shafts, there is frictional connectivity (interlocking action) between the key, main shaft and the tie plate. This further strengthens the connection made.
It is to be appreciated that the length of the key way, the length of the key, the length of the friction wedges and the length of the bottom tapers of the key may all be varied and provided in different combinations. In one aspect, these lengths may be established so that the tapered end of the key begins to bend and protrude into the medium just as the friction wedges make contact with the sides of the key way. In another aspect, the key may be so long that the end of the key is already protruding well into the medium by the time the friction wedges begin to cut into the key way. Numerous other aspects and combinations may be utilized depending upon the desires of the user.
Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to
The directional shape of key 50 and key way 43 also assure that the friction wedges 54 of key 50 are properly aligned so that they make contact with one or more of the sides of key way 43. As the friction wedges 54 on key 50 are driven downward into key way 43 they self-cut grooves 46 (
The progression of insertion is illustrated in
It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof. It is also to be understood that the present invention is not to be limited by the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the foregoing specification. Among other things, a key can be used to clear or remove a broken key lodged in the key way. In particular, although many of the illustrations are directed toward an embodiment for use with a railroad spike, tie plate, and tie system, it is to be appreciated that slightly modified versions of the present invention may be utilized in bridge systems, piers, or other support structures made of wood or other similar materials. Specifically, although the bottom 57 of key 50 is shown as tapered 56 on both sides, it is to be appreciated that any number of sides may be tapered in such a manner, or that no tapering may be provided at all. Similarly, although the drawings depict key 50 as directional and rectangular, it is to be appreciated that key 50 may be of any suitable directional shape or size. Similarly, although the drawings depict key 50 with a rectangular shaft, it is to be appreciated that key 50 may have any spike or shaft that corresponds in shape to tapered key way 43. Finally, although two friction wedges 54 are illustrated in the drawings, any suitable number may be used, depending upon the size and shape of the key 50 and key way 43.
