Abstract:
A model toy train track assembly provides separate electrical and mechanical locking or snap-together connections. A molded base of each track assembly has a protruding U-shaped feature on each end that physically joins to track assemblies or sections when pressed into a complementary receiving slot. To provide a reliable electrical connection, metal connectors corresponding to each of the rails lock into receiving connector slots of the adjoining track section. Alignment ribs on opposite sides of each rail ensure straight and accurate alignment of the rails. To prevent slipping of the rails, each rail is staked into the molded base. The rails are tubular and sized and positioned so as to provide compatibility with conventional two-rail or three-rail tubular tracks of similar gauge.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/160,881, filed Oct. 22, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     As is often the case, smaller, less obvious items are more crucial than the more austere and more eye-catching features. The importance of track to the model toy railroad industry can not be overemphasized; a train set can be beautifully crafted and engineered, but without a reliable, well-constructed track to run it on, the whole objective is defeated. The crucial factor in track layout and operation is continuous and constant mechanical and electrical connections without which the toy train will cease running or may derail. This is why track itself is a main focus of and is critical to model railroadry and why so much time and research are factored into the designs as well as the constant striving for improvements. 
     For a number of years, the common solution to maintaining this critical connection was only through mechanical means. In several inventions, the electrical current is maintained solely through direct rail to rail contact; the purpose of the mechanical invention, then, is to devise a secure contact or touching of the track rails themselves. However, in each case, if there is a separation of the mechanical features due to causes such as vibrations from the train running on the track or weakening of parts with age or other various factors, the electrical current is lost as well. 
     DESCRIPTION OF PRIOR ART 
     Traditionally, the basic model railroad track has been designed and produced with tubular rails formed from long, thin strips of tin sheet metal which are roll formed, a process of bending and shaping, to simulate the appearance of actual rails. This method was used not only for aesthetic reasons, but also provided the actual physical and electrical connections of the train layout. Although not the main focus of either U.S. Pat. Nos. 4,771,943 or 5,529,241, this type of tubular rail can be identified by examining these two patents. A common solution for tubular rail connection, if no other mechanical means of maintaining rail contact existed, was inserting, into the hollow rails, a rail connection, also known as a track pin, to connect two adjoining rails. A key problem re-occurring with inventions that solely rely on utilizing thin sheet metal to maintain connection is that sheet metal easily bends out of the originally formed shape and, thus, can lose its secure, close fit. 
     Aside from the common and traditional use of rail connectors, one approach to the problem of maintaining constant and continuous connection has been to attach an auxiliary and augmenting part to the track assembly itself. The thin sheet metal joints in U.S. Pat. No. 4,225,081, which connect directly onto the rails, provide additional connection but have the same tendency as other sheet metal products to bend out of the original shape and to lose the close contact as the rails are wiggled in and out. 
     U.S. Pat. No. 4,223,843 includes an elongated U-shaped sheet metal clamp to join the track sections. The flat, elongated section of the clamp lies beneath each rail section of two adjoining track sections, while the U-shaped clamp parts extend upwards between the crossties to hold the rails. The limited design of the clamp will only allow for use with track section of a particular base design and with particular crosstie spacing. 
     U.S. Pat. Nos. 4,993,631 and 5,139,198 by the same inventor, has a unique design of a separate solid figure-eight shaped connection element which fits into recesses formed into the underside of the solid ballast-type track bed body. Although providing both electrical and mechanical connections, this attachable connecting element presents a more complicated means of track connection than typical solutions in the model toy train industry. 
     A different type of approach evolved, involving only mechanical connections, by introducing various protruding and receiving elements formed as part of the molded plastic track bed base. However, electrical contact was still solely dependent upon a close contact of the rails themselves, as no locking feature of the rails or additional electrical connectors were incorporated into the designs. If the mechanical connections loosen or separate, a gap between the rails will terminate the electrical current required for train operation. An example of this approach, U.S. Pat. No. 4,953,785 has, as part of the molded base, a series of interlocking protruding tongue elements and receiving slot elements to physically attach like track sections. 
     In U.S. Pat. No. 4,955,537, a separate lattice-like structure attaches to the underside of the molded track bed; it is this addition to the track bed which has a protruding two-prong fork shape element which locks into a complementary receiving slot. U.S. Pat. No. 5,690,278 has a somewhat more unique laterally offset track bed base with extending and recessed portions which result in a minimum of two locking positions of identical adjacent track sections. 
     A third approach has been to combine both of these two methods mentioned above by incorporating a design which has the sheet metal joint, as already discussed as U.S. Pat. No. 4,225,081, and a track bed base connection consisting of a protruding tongue-type element and a receiving slot-type element. U.S. Pat. No. 4,898,356 is such an invention which incorporates both a sheet metal joint connecting the rails and a rigid plastic tongue and socket concept connecting the base. 
     Likewise, U.S. Pat. Nos. 5,503,330, and 5,752,678 by the same inventor, utilizes the metallic joint on the rails as well as an open-ended, hook-like projection that bends and secures itself into a receiving slot. Unfortunately, with all of these approaches, as the tracks are connected and re-connected, the track sections have a tendency to fit together less securely over time, thereby allowing gaps between the rails, which result in loss of electrical connection and current. 
     In most recent years, in the field of model railroadry, a transition has been made towards what is frequently known as “snap-together” track, which has a plastic base, either solid or a crosstie lattice, that joins track sections together to provide the physical means of connection, while a separate system of metal connectors provide the electrical connection required for a continuous electrical current throughout the system. 
     A track assembly with both mechanical and electrical connection systems is seen in U.S. Pat. No. 4,709,856. In this invention, as part of the design, the locking elements consist of one which is upwardly open and the another element which consists of two parallel springs with a recess between said springs. The design has been incorporated specifically into the manufacture of the smaller type gauge track having a ballast-type track bed base and solid rails and can only be used in conjunction with identical track sections. 
     SUMMARY OF THE INVENTION 
     The present invention is the first to incorporate both the traditional tubular rails and the recent snap-together type track, which incorporates separate, yet complementary, electrical and mechanical connection systems into one design which can be used with not only identical track sections but also with any manufacturer&#39;s tubular track of the same gauge. The features and positioning of the mechanical and electrical connectors allow for use of these track sections with the common, traditional tubular track sections that have been widely manufactured. In addition, although a major irritation to track manufacturers, the problem of rails sliding and slipping from position has been addressed infrequently in previous inventions. Improvements in this area are part of the present invention as well. 
     The present invention has at least the following objectives: to provide secure and reliable mechanical and electrical track assemblies, to create a unique dual compatibility system of both tubular and snap-together track, to prevent lengthwise sliding of rails, and to prevent lateral sliding of the rails. 
     The present invention provides a model toy train track assembly which addresses improvements to four areas of concern in the model railroad industry: mechanical and electrical connection maintenance, compatibility with other manufactured train track, tubular rail alignment, and rail slideage. A solution to maintaining connection has been provided by two separate mechanical and electrical systems. The tubular quality of the rails allows for dual use with an O gauge tubular track, regardless of the manufacturer. Two alignment ribs positioned against each rail on the end crosstie ensure a straight and even alignment of juxtaposed rails from two joining track sections. To prevent slipping and sliding of the rails on the track bed, each rail is staked into the track bed base. 
     In accordance with the present invention, a model toy train track assembly comprises three tubular rails attached to a simulated crosstie molded track bed. Each rail is formed from a single narrow, thin sheet of metal bent and shaped to the common shape of a railroad track rail. The rails run parallel to each other along the length of the track bed. The track bed itself is a one-piece lattice-type structure that, upon attachment of the rails, resembles wood crossties when viewed from the top and sides to create a traditional, realistic railroad track. 
     The elements of the physical or mechanical connection system, which join track sections together, are incorporated into the basic molded plastic structure of the track bed base. The structure at the end of each piece of track is duplicated at the other end of the same track piece, the structure comprising a flexible, hollow U-shaped protruding tongue projecting outward from and in the same direction as the leftmost rail when viewed from the bottom side. The middle rail does not have any features assisting in the mechanical connection, whereas the rightmost rail has a formed receiving slot element to lock in the protruding U-shaped tongue element coinciding with the next adjoining track section. In addition, immediately between the rightmost rail and the end crosstie is a rectangular ledge with slightly raised edges to guide the rail from the adjoining section into place. 
     The main element of the electrical connection system is comprised of a thin metal connector. The connector is located on the underneath side of the plastic track bed base, situated flush with the end sections of that base, corresponding directly to a rail. Thus, each end section of track has three connectors, one for each rail, with a total of six of these identical connectors per track piece. The connectors are physically attached to the track assembly by two means. First, circular holes cut into the sheet metal allow the connector to snap down onto two round projections which are part of the molded track bed base. Second, two side strips of sheet metal that span out from the main section of sheet metal are wrapped up and around each section of track bed below the rails, thereby not only providing attachment to the track bed but also creating and maintaining contact of the connectors with the rails. 
     While these two features provide connector-to-rail contact, the contact between electrical connectors of two adjoining track sections is realized by complementary protruding and receiving elements of the connectors themselves. A rectangular plastic divider protruding up through the middle of the outwardmost end of the electrical connector from the track bed base divides the outermost, attaching end of the connector into two sections. Looking from the bottom perspective of a track section, the rightmost side of the electrical connector implements two protruding strips of metal which fold together to form a closed extension. Each of these extensions inserts into a complementary receiving area of the opposing adjoining connector. A well-secured fit of the protruding extension is accomplished by 1) the presence of the plastic divider, and by 2) the side wall of the mechanical locking elements and the second of the receiving metal connectors that bends up to form an edge along this side wall. 
     A track section is designed to join together agreeably with identical track sections of the same manufacturer. As a result, whenever a new design of track is introduced, a hobbyist or user of a toy train setup must purchase enough of the new type of track to complete the desired layout. This particular invention introduces a track system whereby the track pieces can be connected not only with identical track sections but also with any tubular O gauge track from any manufacturer which establishes its mechanical and electrical connections through track pins that insert into the tubular rails. The tubular rail and track pin combination is a common and popular method of rail connection. The tubular rail feature of the present invention allows instant and universal compatibility of tubular rail track sections which benefits users and hobbyists who already own tubular track. Instead of requiring the model train operator to purchase an entire new track system, often at great expense, these track sections can supplement and augment an operator&#39;s existing collection of track pieces. 
     In addition, to enhance the benefit of the tubular rails, alignment ribs or guides have been added to maximize alignment of the rails at the critical point of contact with adjoining rails. Situated on the top side of each of the two end crossties of the track bed are two alignment ribs per rail which rise up from the plastic molded base and press against the rail to prevent bending or shifting of the rails. The plastic alignment ribs come up at right angles next to the lower straight sections of the metal rails. Although, these are not connected to the rails, they prevent lateral movement of the rails. Since the alignment ribs are located in close proximity to an adjacent joining track, a uniform alignment of the two rail sections is accomplished. 
     This particular track invention addresses another problem common to model railroadry, which is the sliding and slipping of rails on the track bed. The present improvement is to stake a small area of the lower section of the rail, which lies flat against the track bed, into a hole implemented into the design of the molded track bed base. The force of the staking and the bendability of the sheet metal provides a secure attachment which then prevents lateral and lengthwise movement of the rails. For each track section, this staking is implemented at two points for each rail, for example, at the fourth crosstie from each end of a track section. In order to hold the rails more tightly and prevent lateral movement of the rails, brackets simulating rail spikes are provided on some of the crossties. A ridge on the underside of each bracket holds the rail down tightly against the tie. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a top plan view of one section of electric model railroad toy train track according to the invention. 
     FIG. 2 is a bottom plan view of the track section of FIG.  1 . 
     FIG. 3 is an enlarged partial perspective top view of the track section of FIG. 1, emphasizing the tubular rails, the alignment ribs, and the staked area of the rails. 
     FIG. 4 is an enlarged cross-sectional view of one of the tubular rails, taken along the line  4 — 4  in FIG.  3 . 
     FIG. 5 is an end view of the track section of FIG. 3 with the rails. 
     FIG. 6 is a partial top plan view of the track section of FIG. 3 with the rails removed. 
     FIG. 7 is a partial plan view of two end sections of track in alignment with one another but unjoined. 
     FIG. 8 is a partial bottom plan view of the two track sections of FIG. 7 joined together. 
     FIG. 9 is a bottom plan view of the track sections of FIG.  8 . 
     FIG. 10 is a bottom plan view of the track sections of FIG.  7 . 
     FIG. 11 is an enlarged partial bottom plan view of the track sections of FIG. 9 emphasizing the mechanical and electrical connection elements. 
     FIG. 12 is an enlarged bottom plan view of one of the electrical connections of one of the track sections of FIG.  10 . 
     FIG. 13 is an enlarged perspective view of a portion of track section with the rail removed, showing rail brackets. 
     FIG. 14 is a further enlarged perspective view of the underside of one of the brackets, showing a ridge. 
     FIG. 15 is an enlarged cross-sectional view of a portion of track section, taken through a crosstie and showing the staking of one of the rails. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As can be seen from FIGS. 1-4, each model railroad electrical toy train track assembly, which is designated generally by the reference numeral  2 , comprises three rails  4 ,  6 ,  8 , each formed from one long thin piece of electrically conductive sheet metal through a process of bending and shaping known as roll forming, so that the middle of the narrowest section of each sheet creates a round hollow crown  10  that defines a tunnel extending the length of each sheet. From that point the portions of each rail on both sides of the crown  10  extend straight down towards a bed base  16 , and the ends  18 ,  20  bend outward and lie flat with lengthwise portions of the molded plastic base  16 . The molded base  16  has three such lengthwise portions  22 ,  24 ,  26 , each corresponding to one of the three rails  4 ,  6 ,  8 . To attach the rails  4 ,  6 ,  8  to the track bed base  16 , the rails  4 ,  6 ,  8  are slid along parallel to the lengthwise base portions  22 ,  24 ,  26  through gaps in plastic rail spikes  28  and alignment ribs  30   a,    30   b  that are part of the molded track bed base  16  until the rails and base are flush at each end. Referring to FIGS. 5 and 6, the alignment ribs  30   a,    30   b  prevent lateral movement and bending of the rails  4 ,  6 ,  8 , and the location of the alignment ribs on the two endmost crossties  40   a,    40   b  provide rail alignment where it is most needed—in close proximity to the corresponding rail of an adjoining track section. By staking, small areas  34  of the flat thin sheet metal of the laterally outward ends  18 ,  20  of the tubular rails are pressed or staked into depressions  36  formed in the molded track bed base  16 . This restrains the rails  4 ,  6 ,  8  from sliding freely through the rail spikes  28  and the alignment ribs  30   a,    30   b.    
     As can be seen from the bottom view of FIG. 2, the molded plastic track bed base  16  has a lattice-type pattern wherein the three lengthwise portions  22 ,  24 ,  26  of the lattice are directly below and touching the rails  4 ,  6 ,  8 , and widthwise elements of the lattice define crossties  40  which are perpendicular to the three lengthwise sections  22 ,  24 ,  26 . These crossties  40  are hollow and open on the bottom side but, except for the two crossties  40   a  and  40   b  closest to each end of a track section, are closed on all other sides. The top of each crosstie  40  has ridges and grooves to give the appearance of wooden railroad ties. The crossties  40   a  and  40   b  at each end have additional open portions to make allowance for the mechanical and electrical connecting features. As can be seen from FIG. 1, when the rails  4 ,  6 ,  8  are in place, the lengthwise portions  22 ,  24 ,  26  are not immediately apparent. Instead, the simulated crossties  40  of the molded base  16  are seen as the prominent feature of the base. 
     The track section connecting features comprise two separate, yet complementary, systems, one mechanical in nature and one primarily electrical in nature. The mechanical connection system is comprised of elements that are part of the molded plastic form of the base. As can be seen from FIGS. 2,  9 ,  10 ,  11 , the crossties  40   a  and  40   b  and associated protruding and receiving connecting elements are situated such that a protruding U-shaped element  42  associated with the leftmost rail  4  extends and joins to a receiving slot element  44  associated with the rightmost rail  8  of the connecting track section. The U-shaped protruding element  42  is flexible enough to bend in slightly to fit into the corresponding shape of the receiving slot element  44  which consists mainly of two side walls  44   a,    44   b  curving inward, that are not connected to each other. As a result, the U-shaped protruding element  42  snaps into the receiving slot element  44 . Several features aid in the proper placement and secure fit of the two connecting elements. Protruding bumps  46  in the protruding, U-shaped element pop into corresponding grooves  48  of the receiving slot. The several side walls  50  of the two end crossties  40   a  and  40   b  are formed to provide additional structure and support for the protruding element  42 . The side walls  44   a,    44   b  help provide a secure fit and help prevent breakage of the protruding U-shaped element  42 . An additional feature is an alignment ledge  52 , with slightly raised edges  54   a,    54   b,  located directly below the left rail  4  associated with the receiving slot element  44 . This alignment ledge  52  aids in guiding the adjoining rail section. A recess  55  is defined at each end of the track assembly  2  in an upper surface of the base  16  directly under the associated rail  4  or  8 . The associated rail  4  or  8  terminates in the same vertical pane as the rail and defines with the recess  55  a space for receiving the ledge  52  of a like track assembly. The recess  55  has side walls  55   a  and  55   b.  The distance between the side walls  55   a  and  55   b  of the recess  55  is just slightly greater than the width of the alignment ledge  52 . The raised edges  54   a  and  54   b  of the alignment ledge extend upward along outer edges of the ends  18  and  20  of the rail. The distance between the raised edges  54   a  and  54   b  is just slightly greater than the width of the rail at the ends  18  and  20 . 
     The primary element of the electrical connection system is a mainly rectangular, sheet metal connector  56 . Now referring to FIGS. 2,  9 ,  10 ,  11  and  12 , this connector  56  is located on the underside of the plastic track bed base  16  adjacent to a rail. Thus each end of a track section has three connectors  56 , one for each rail, with a total of six of these identical connectors  56  per track assembly  2 . Although mainly rectangular in appearance, the sheet metal is cut in several areas to accommodate features and functions of the connector  52 . Two of the features provide the physical attachment to the track bed base  16  and the rails  4 ,  6 ,  8 . Circular holes  58 ,  60  are cut into the connector to allow the connector  56  to snap down onto two cylinder-shaped projections  62 ,  64  which are part of the molded track bed base  16 . Additionally, two side strips  66 ,  68  of the connector extend out from the main section of sheet metal and wrap up and around each section of track bed  16  and contact with the rails  4 ,  6 ,  8 , thereby, not only providing attachment of the connector to the track bed base  16  but also creating and maintaining contact of the connectors  56  with the rails  4 ,  6 ,  8 . A rectangular section  70  cut out from an area between these two attaching metal strips  66 ,  68  backs up against a plastic rectangular element  72  projecting out from the plastic molded base  16 . This plastic projecting element  72  is a guide to align the connector  56  into the correct position and prevent lateral movement of the connector  56 . 
     Other features of the connector  56  relate more to the connection of two opposing connectors  56  from adjoining track sections. From one side of a connector  56 , two protruding strips of metal  74 ,  76  fold together to form a closed extension  78 . Each of these extensions  78  extends into a complementary receiving area  80  of an adjoining connector  56 . Near the two circular holes, a rectangular opening  82  is cut out to provide room for a plastic rectangular element  84  projecting out from the plastic molded base. This plastic protruding element  84  creates a divider between the protruding connector extension  78  and the connector receiving area  80 . In conjunction with the dividers  84 , flanges  86  and  88  along edges of the connector  56  extend up the crosstie walls  50  and provide a secure fit for the protruding connector extension  78  as the extension locks into the connector receiving area  80 , with the extension being resiliently biased by its shape and material into engagement with the flange  86 . The extension  78  is defined in part by the flange  88 . 
     As can be seen from FIGS. 13 and 14, in order to hold the rails  4 ,  6 ,  8  more tightly and prevent lateral movement of the rails, brackets simulating rail spikes  28  are provided in some of the crossties  16 . A ridge  90  on the underside of each bracket holds the rail down tightly against the tie. 
     As can be appreciated from FIG. 15, small areas  34  of the laterally outward ends  18 ,  20  of each rail  4 ,  6 ,  8 , which lie flat against the track bed, are staked into the molded track bed base  16 , forming a hole  36 . The force of the staking and the bendability of the sheet metal of the rails provides a secure attachment which then prevents lateral and lengthwise movement of the rails. For each track section, this staking is implemented at two points for each rail, for example, at the fourth crosstie from each end of a track section  2 . 
     It will be apparent to those skilled in the art and it is contemplated that variations and/or changes in the embodiments illustrated and described herein may be made without departure from the present invention. Accordingly, it is intended that the foregoing description is illustrative only, no limiting, and that the true spirit and scope of the present invention will be determined by the appended claims.