Abstract:
A rail road car has a deck for carrying wheeled vehicles. The vehicles are loaded from the ground by use of a movable ramp that is positioned next to a separate coupler end of the rail road car. The ramp has a locating guide, in the nature of a pair of tapered prongs, that locate in mating sockets in the end of the rail road car. The co-operation of the guides and sockets forces the ramp to align with the deck of the rail road car in a predetermined position, namely aligned centrally with the deck. The ramp has a telescoping, pivoting boom. The boom has a hitch that can be engaged by a towing vehicle, permitting the ramp to be moved into position as desired. The boom can then be collapsed and lowered out of the way of the path of the wheeled vehicles. The boom is counterweighted to facilitate manual operation.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of rail road cars for carrying wheeled vehicles, and, in particular, to apparatus and a method for loading vehicle carrying rail road cars. 
     BACKGROUND OF THE INVENTION 
     Railroad flat cars are often used to transport highway trailers from one place to another. One method of loading highway trailers, or other wheeled vehicles onto rail road cars having decks for carrying vehicles is by what is called circus loading. A ramp is placed at one end of a string of rail car units, and then each vehicle is loaded in sequence by driving along the decks of the rail road car units. The gaps between successive rail car units are spanned by bridge plates. Although circus loading is common for a string of cars, end-loading can be used for individual rail car units, or multiple rail car units as may be convenient. 
     It is common for movable ramps to be employed to permit trailers to be driven up onto the rail cars. In recent years there has been an emphasis on reducing the loading time required in intermodal service, and in increasing the length of intermodal trains. Another trend has been toward the increased use of articulated rail road cars, as opposed to single unit cars employing standard releasable couplers. Articulated rail road cars are often able to carry the same number of highway trailers as single unit cars, but have fewer rail car trucks, thus increasing the lading per truck, reducing the effective ratio of the railcar weight to lading weight, and reducing the slack action along the train consist in service. 
     When a large number of articulated cars are used, and a lengthy train is to be loaded, it is important that loading proceed in an orderly and efficient manner. The railcars are split at the releasable coupler ends, ramps are moved into place, and wheeled vehicles are loaded in both directions running away from the location of the split. Once loaded, the train is re-assembled by re-joining the coupler ends, and the train departs the loading terminal. The loading of highway trailers has certain special features. First, the highway trailers are backed into position sequentially using a hostler truck, or tractor. Backing a highway trailer on a flat car is a task requiring some care. It is advantageous to align the loading ramp well before commencing loading of the trailers. 
     At present, time is often wasted aligning the ramps. It would be highly advantageous to have a ramp that can be aligned relatively quickly and easily. 
     SUMMARY OF THE INVENTION 
     In an aspect of the invention there is a movable ramp operable to permit wheeled vehicles to be end-loaded onto a deck of a rail road car. The ramp has a trackway assembly along which vehicles can be conducted and a set of wheels to which the trackway assembly is mounted. The wheels facilitate positioning of the trackway assembly relative to the rail road car. The trackway assembly has a first end locatable next to an end of the rail road car, and a second end locatable away from the rail road car next to a base surface that is lower than the deck of the rail road car. At least one guide extends proud of the first end of the trackway assembly. The guide is operable to locate the first end of the ramp relative to the deck, whereby, when the first end is located next to the end of the rail road car, and the second end is located next to the base surface, wheeled vehicles can be conducted between the rail road car deck and the base surface along the trackway assembly. 
     In an additional feature of that aspect of the invention, the set of wheels includes an axle and a pair of wheels mounted thereto. The axle is mounted at least as close to the first end of the trackway assembly as to the second end thereof In another additional feature, the ramp has a hitch locatable proud of the second end of the trackway assembly, to permit positioning of the ramp by a driving vehicle. In still another additional feature, the guide has a portion that is at least partially tapered, and the at least partially tapered portion is engageable with a structural feature of the railroad car to facilitate alignment of the first end of the trackway assembly relative to the deck of the rail road car. In yet another additional feature, the guide is engageable with a structural member of the rail road car, and the guide is operable to support the first end of the trackway assembly while the wheeled vehicles are conducted between the first and second ends of the trackway assembly. 
     In a further feature, the guide is a prong mounted to engage a socket of the rail road car. In still a further feature, at least one guide includes a pair of spaced apart prongs mounted to engage the rail road car. In yet a further additional feature, the ramp has a longitudinal direction defined between the first and second ends of the trackway assembly, and a transverse direction defined across the trackway assembly. At least one guide is a pair of transversely spaced fork tines. In another additional feature, the tines are engaged with the rail road car. The tines are operable to support the first end of the trackway assembly while wheeled vehicles are conducted between the first and second ends of the trackway assembly. In still another additional feature, the tines have tapered tips to facilitate alignment of the ramp with the rail road car. 
     In another aspect of the invention there is a movable ramp and rail road car set. The set has a rail road car having a first end, a second end, and a deck upon which vehicles can be end-loaded. The first end of the rail road car has at least one indexing member. A ramp has a trackway assembly along which vehicles can be conducted and a set of wheels to which the trackway assembly is mounted. The wheels facilitate positioning of the trackway assembly relative to the rail road car. The trackway assembly has a first end locatable next to an end of the rail road car, and a second end locatable away from the rail road car next to a base surface that is lower than the deck of the rail road car. At least one guide extends proud of the first end of the trackway assembly. The guide is operable to engage the indexing member to facilitate alignment of the trackway assembly with the first end of the rail road car. 
     In an additional feature of that aspect of the invention, the indexing member is a socket defined in the first end of the rail road car. The guide is formed to mate with the socket. In another additional feature, at least one of (a) the guide and (b) the socket, is at least partially tapered. In still another additional feature, the first end has a pair of the sockets and the ramp has a corresponding pair of the guides. In yet another additional feature, the sockets are transversely spaced relative to the deck. In a further additional feature, the rail road car has an end sill, and the sockets are defined in the end sill. 
     In still a further additional feature, the guide is engageable with a structural member of the rail road car, and the guide is operable to support the first end of the trackway assembly while the wheeled vehicles are conducted between the first and second ends of the trackway assembly. In yet a further additional feature, the ramp has a longitudinal direction defined between the first and second ends of the trackway assembly, and a transverse direction defined across the trackway assembly. At least one guide is a pair of transversely spaced fork tines. In another additional feature of that aspect of the invention, the tines are engaged with the rail road car. The tines are operable to support the first end of the trackway assembly while wheeled vehicles are conducted between the first and second ends of the trackway assembly. In still another additional feature of that aspect of the invention, the tines have tapered tips to facilitate alignment of the ramp with the rail road car. 
     In another aspect of the invention there is a process of loading wheeled vehicles onto a rail road car. The process includes the steps of providing a rail road car having a first end, a second end, and a deck upon which vehicles can be end-loaded. The first end of the rail road car has at least one indexing member providing a ramp having a trackway assembly along which vehicles can be conducted and a set of wheels to which the trackway assembly is mounted. The wheels facilitate positioning of the trackway assembly relative to the rail road car. The trackway assembly has a first end locatable next to an end of the rail road car, and a second end locatable away from the rail road car next to a base surface that is lower than the deck of the rail road car. At least one guide extends proud of the first end of the trackway assembly. The guide is operable to engage the indexing member to facilitate alignment of the trackway assembly with the first end of the rail road car engaging the guide with the indexing member, advancing the guide relative to the indexing member to align the trackway assembly with the deck of the railroad car and conducting vehicles over the trackway assembly between the base surface and the deck. 
     In an additional feature of that aspect of the invention, the step of advancing includes moving the guide from a loose engagement position relative to the indexing member, to a seated position. In another additional feature, the rail road car has a longitudinal axis wherein the step of advancing includes the step of centering the trackway assembly relative to the longitudinal axis of the rail road car. In a further additional feature, the guide is used to support the first end of the trackway assembly while conducting vehicles between the base surface and the deck. 
     In still another aspect of the invention, there is a movable ramp operable to permit wheeled vehicles to be end-loaded onto a deck of a rail road car. The ramp comprising includes a trackway assembly along which vehicles can be conducted. The ramp has a set of wheels. The trackway assembly is mounted on the set of wheels. The wheels facilitate positioning of the trackway assembly relative to the rail road car. The trackway assembly has a first end locatable next to an end of the rail road car, and a second end locatable away from the rail road car next to a base surface that is lower than the deck of the rail road car. A pivotable boom is connected to the trackway assembly. The pivotable boom has a hitch attachment mounted to one end thereof. The pivotable boom is movable between a first position and a second position. In the first position the hitch is presented for engagement by a ramp manoeuvering vehicle. In the second position the trackway assembly is free of obstruction by the boom. 
     In an additional feature of this aspect of the invention, the boom is counterweighted. In another feature, the boom is a telescoping boom. In the first position the telescoping boom is in an extended condition. In the second position the telescoping boom is in a retracted position. 
     In another additional feature, the boom includes a first portion pivotally mounted to the trackway assembly, and a second portion mounted to slide telescopingly relative to the first portion. In a further additional feature, the boom has a first end and a second end and pivots about a fulcrum intermediate the first and second ends. The hitch attachment is mounted to the first end. The first portion is movable relative to the second portion to extend the hitch attachment between extended and retracted positions relative to the fulcrum. A counterweight is mounted to the second end of the boom. 
     In a still further additional feature the ramp has a movable support member operable to secure the boom in a fixed angular position relative to the fulcrum when the first end of the boom is in the extended position. In still another feature, the ramp has a locking member operable to secure the first portion in the extended position relative to the second portion. In a further feature, the locking member is releasable to permit the first portion to be moved between the extended and retracted positions relative to the second portion, and is operable to secure the first portion in the extended position and in the retracted position. The movable support member is operable to maintain the second portion in a raised position to the trackway assembly, the hitch attachment being proud of the trackway assembly when the second portion of the boom is in the raised position. The first portion has handles to facilitate movement between the extended and retracted positions when the second portion is in the raised position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  shows a conceptual top view of an articulated vehicle carrying rail road car, in an unloaded condition; 
     FIG. 1 b  shows the articulated rail car of FIG. 1 a  in a split configuration ready for loading; 
     FIG. 1 c  shows the articulated rail road car of FIG. 1 a  in a partially loaded condition; 
     FIG. 1 d  shows the articulated rail road car of FIG. 1 a  in a fully loaded condition; 
     FIG. 1 e  shows the rail road car of FIG. 1 a  in a loaded, assembled condition. 
     FIG. 2 a  shows a top view of a ramp for use with the rail road car of FIG. 1 a;    
     FIG. 2 b  shows a side view of the ramp of FIG. 2 a;    
     FIG. 2 c  shows a side view of the ramp of FIG. 2 a  showing its boom in a telescopically collapsed position; 
     FIG. 3 a  shows a partial perspective end view of one of the rail car units of the rail road car of FIG. 1 a , with the bridge plate in a deployed position; 
     FIG. 3 b  shows a similar view to that of FIG. 3 a , with the bridge plate in a stored position; 
     FIG. 4 shows an end view of the rail car unit of FIG. 3 a.   
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The description that follows, and the embodiments described therein, are provided by way of illustration of an example, or examples of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features of the invention. 
     In terms of general orientation and directional nomenclature, for each of the rail road cars described herein, the longitudinal direction is defined as being coincident with the rolling direction of the car, or car unit, when located on tangent (that is, straight) track. In the case of a car having a center sill, whether a through center sill or stub sill, the longitudinal direction is parallel to the center sill, and parallel to the side sills, if any. Unless otherwise noted, vertical, or upward and downward are terms that are use top of rail TOR as a datum. The term lateral, or laterally outboard, refers to a distance or orientation relative to the longitudinal centerline of the rail road car, or car unit, indicated as CL—Rail Car. The term “longitudinally inboard”, or “longitudinally outboard” is a distance taken relative to a mid-span lateral section of the car, or car unit. 
     By way of general overview, FIGS. 1 a  to  1   e  illustrate the process of loading a multi-unit articulated rail road car. In this example, an articulated rail road car assembly includes a pair of articulated three-pack articulated rail road cars  22  and  24  joined together to form a six rail car unit assembly. There are first and second end units  26 , and  28 , intermediate articulated units  30  and  32 , an intermediate coupled units  34  and  36 . A locomotive is shown schematically as  38 , a hostler truck is shown schematically as  40 , and various highway trailers are shown as  42 . For the purposes of this description, it can be taken that units  26  and  28  are the same, units  30  and  32  are the same, and units  34  and  36  are the same. Rail car units  26  and  30 ,  30  and  34 ,  36  and  32 , and  32  and  28  are joined together by articulated connections mounted over their respective articulated connection trucks. Rail car units  34  and  36  are joined by releasable couplers  44 ,  46 . The gaps between rail car units  26  and  30 ,  30  and  34 ,  36  and  32 , and  32  and  28  are spanned by permanently mounted bridge plates  47 ,  48 ,  49  and  50 . Rail car units  34  and  36  are joined by movable bridge plates  58 , such that the respective decks  51 ,  52 ,  53 ,  54 ,  55  and  56  form continuous pathways upon which vehicles can be driven. If additional rail road cars are joined at the opposite ends of rail road cars  22  and  24 , further bridge plates can be employed to extend the length of the path. 
     For the purposes of this description, articulated cars, or combinations of articulated cars having any reasonable number of articulation units can be employed. 2-unit, 3-unit, and 5-unit articulated packs are relatively common. 
     In FIG. 1 b , three pack rail car units  22  and  24  are separated by some distance, typically several hundred feet. Bridge plates  58  are moved to their stored positions. Movable ramps  60  are manoeuvred into position by hostler trucks  40  adjacent the respective separated ends of units  34  and  36 . 
     In FIG. 1 c , ramps  60  remain in place. Hostler trucks  40  have been disconnected from ramps  60  and used to load trailers  42 . In FIG. 1 d , rail road cars  22  and  24  are in a loaded condition. Hostler trucks  40  are again hitched to ramps  60  to draw them clear of the rail way. In FIG. 1 e , rail road car assembly has been joined together again, and is ready to be hauled to its destination. Once it has arrived, the series of steps of FIGS. 1 a  to  1   e  can be reversed, and trailers  42  unloaded. 
     Ramp  60  is shown in greater detail in FIGS. 2 a  and  2   b . It has a trackway assembly  62 , having a first end  64  for placement adjacent to the nearest end of the rail road car that is to be loaded, such as, for example, the separated ends of either or rail car units  34  and  36  of rail road cars  22  and  24  respectively. First end  64  is positionable at a height corresponding to the deck height of the adjacent rail road car. Trackway assembly  62  also has a second end  66 , located distant from first end  64 , and, in use distant from the end-loading end of the adjacent rail car unit. Second end  66  is the lower end, and is to be placed against a base surface, such as the ground, or a concrete or asphalt pad from which highway trailers are to be driven onto rail road cars  22  and  24 . 
     First end  64  is mounted above a wheel set, in the nature of an axle  65  and a pair of left and right hand wheels  68 ,  70 . Axle  65  is mounted closer to first end  64  than to second end  66 . A manoeuvering fitting, or hitch attachment in the nature of a king pin hitch  72  is provided by which a manoeuvering apparatus such as a tractor, or such as hostler truck  40  can engage ramp  60  and manoeuvre ramp  60  into position adjacent to the loading end of the rail road car. Hitch  72  extends proud of (that is, longitudinally beyond) the distal extremity of second end  66 , and is mounted on a pivoting, telescoping boom  74 . When hostler truck  40  is disengaged, boom  74 , and hence hitch  72 , can be released from the raised and extended position shown in FIG. 2 b , by removing a securing or locking member, in the nature of a pin  71  from position ‘B’ shown in FIG. 2 a . The inner telescoping portion  73  of boom  74  is slidingly engaged within, and can be collapsed telescopically within, the outer hollow tube portion  75  of boom  74 , as shown in FIG. 2 c . Gripping members, in the nature of hand grabs or handles  69  are mounted adjacent to king pin hitch  72  to facilitate retraction, or collapse, (and, alternatively, extension) of boom  74 . Pin  71  can be reinserted in position ‘C’, shown in dashed lines in FIG. 2 a , to secure portion  73  in its collapsed position relative to portion  75 . 
     A counter-biasing member, in the nature of a counter-weight  77  is mounted at the far end (that is, the end away from pin  71 ) of portion  75  such that when portion  73  is in the retracted, or collapsed, position of FIG. 2 c , boom  74  is balanced to pivot on a pivot axle, or bar, indicated as fulcrum  79 . It will be appreciated that, ideally, the counter-balancing should be very close to equal, so that boom  74  balances evenly, and can be manipulated relatively easily by hand operation. However, hand operation will be satisfactory even where the boom is not precisely balanced. That is, in the telescopically collapsed, or retracted position, it is desirable that the pivoting force exerted by the operator at handles  69  to either raise or lower boom  74  be less than 50 Lbs., and preferably less than 20 Lbs. 
     A movable support, stay, or prop, in the nature of a releasable strut  81  is engaged to secure boom  74  in the raised position with hitch  72  proud of trackway assembly  62 , and is disengaged from its upright, or vertical, position to permit boom  74  to pivot as shown by arrow ‘A’ to a lowered, or storage position shy of the profile of trackway  62 , (shown in dashed lines). Boom  74  need not be stored in a position fully shy of trackway  62 , provided hitch  72  is lowered sufficiently to clear the undercarriage of vehicles to be conducted along ramp  60 . However, it is convenient, and conservative, fully to pivot boom  74  to the fully shy position. In the storage position, strut  81  is secured at position ‘D’ (shown in FIG. 2 a , strut  81  being shown in dashed lines in FIG. 2 c  when secured at position ‘D’) and hitch  72  and boom  74  are out of the way, such that they do not impede the loading or unloading of vehicles. When it is time to move ramp  60  again, the steps can be reversed—strut  81  moved away from ‘D’, boom  74  pivoted on its axis, or fulcrum,  79  through the angle of arrow ‘A’ to raise hitch  72  upward, pin  71  removed from position ‘C’, portion  73  drawn outward by using handles  69 , and pin  71  replaced at position ‘B’. All of the steps in moving boom  74  between its operating position (i.e., position for towing) and its storage position, can be performed manually without the aid of a hostler truck or other powered vehicle such as a tractor, loader, or fork-lift. 
     A pair of indexing members, such as first and second ramp guides in the nature of fork tines, or prongs,  76 ,  78  are mounted to extend longitudinally proud (that is outboard) of first end  64  to engage a corresponding structural indexing member of the nearest end of the adjacent rail road car. Prongs  76 ,  78  each have a distal tapered, or conical portion,  80  ending in a rounded tip  82 . In use, as ramp  60  is driven toward a rail road car, (be it  22 ,  24  or some other), one or both of rounded tips  82  will engage the indexing member and tend to follow it as hostler truck  40  continues to advance ramp  60  toward the rail road car. The fit is a loose, or sloppy fit at first, aided by the more forgiving tolerance at the rounded tip and tapered portions of prongs  76 ,  78 . However, as the tapered portions ride against the indexing members, ramp  60  will be forced into a relatively tighter position with much less vertical and lateral tolerance, namely a set, fixed position, or seated position, against the rail car end. This chosen position is longitudinally aligned with the pathway defined by the decking of the adjacent rail road car, and, preferably, is centered relative to the longitudinal axis of the rail road car. The positive location feature of the guides may tend to reduce the need for repeatedly backing and manoeuvring the ramp to achieve the right position, and may tend to eliminate guesswork or discretionary judgement, particularly during loading or unloading operations late at night, or at other times or circumstances when precise alignment skills may be diminished. 
     Considering this structure in greater detail, trackway assembly  62  has a pair of parallel, spaced apart left and right hand tracks, or wheel ways  84  and  86  each having a decking web  87 ,  88  upon which wheeled vehicles can run, a vertical side flange  89 ,  90  having an upwardly extending skirt  91 ,  92  that acts as a curb to guide the wheels of highway trailers, and an inner edge flange  93 ,  94  to stiffen the inner edge of each web. The spacing of the ways is maintained by a transversely extending shear panel  96  at a first end  64  of trackway assembly  62 , shear panel  96  having a wheel-well  102  formed in it; and by a transverse lateral structural member, or cross-member  104  located at second end  66 . Twisting of boom  74  on its pivot fulcrum  79  in the horizontal plane, as when a turning force is exerted by the hostler truck at hitch  72 , is discouraged, or limited by restraining members in the nature of vertical angle irons  108  located longitudinally inboard of cross-member  104 . 
     A transversely extending endwall  110  extends downwardly somewhat inboard of the proximal edges  111  of ways  84  and  86  at first end  64 . A pair of webs  112  and  114  also extend transversely beneath ways  84  and  86 , running laterally inboard from side flanges  89 ,  90  respectively to meet inner edge flanges  93 ,  94 , each web thereby co-operating to form respective relatively stiff, open bottomed boxes. The roots  116  and  118  or shafts, of prongs  76  and  78  extend through (and are welded to) endwall  110 , and through webs  112  and  114  respectively, to which they are also welded. End wall  110  is deflected inwardly in its central portion to accommodate the disconnected coupler end of the adjacent rail road car. 
     Being spaced apart to left and right hand lateral sides of ramp centerline  120 , and rooted thusly, prongs  76 ,  78  are able to bear the structural load of first end  64  when highway trailers, or other wheeled vehicles, ascend or descend trackway assembly  62  between the base surface and the deck of the rail road car adjacent to first end  64 . Thus prongs  76 ,  78  serve the double function of guiding ramp  60  to a seated position, and of carrying the vertical shear load at first end  64  in operation. Retention hooks  122  are provided to discourage ramp  60  from pulling away from the end of the adjacent rail road car unexpectedly. 
     FIGS. 3 a ,  3   b  and  4  show the separated coupling end of a multi-unit articulated rail road car, such as rail road car  22  or  24 , with the releasable coupler removed. For the purposes of description, the rail car unit end of FIG. 3 a  will be described as being the separated end of rail car unit  34  of rail road car  22 , although it could be rail car unit  36 , or some other having the same features. The rail road car longitudinal centerline, at the coupler pocket, is indicated as  100 . 
     Rail car unit  34  has a main deck  53  that is supported by a main center sill, and cross-bearers (not shown), and bounded on its outboard margins by a pair of left and right hand side sills  132 ,  134 . Deck  53  has a central portion, being the top flange  135  of the center sill, bracketed between a pair of wheel ways, or left and right hand wheel paths  136 , 138 . Paths  136  and  138  are each provided with an array of parallel, spaced apart traction bars  140 ,  142 . Deck  53  has a transverse coupler end deck plate  144 , and a downward step, or shelf  146 , lying outboard of plate  144 . The downward step accommodates a bridge plate  148  in its stored position, as shown in FIG. 3 b . Intermediate bridge plate transition plates  152  and  154  are hingedly mounted to plate  144 . In use, the toe of another bridge plate, like bridge plate  148 , from another road car unit, such as rail road car unit  36 , seats under plate  152 . The hinged mounting allows for insertion and removal, and allows for train motion during travel. Shelf  146  terminates at a longitudinally outboard edge that lies over, and is supported by, an end sill  156  having left and right end sill portions  158 ,  160 . Portions  158 ,  160  run between the main sill coupler pocket  162  to left and right hand side sills  132 ,  134  respectively. 
     As shown in FIG. 3 b , each of the left and right hand end sill portions has defined in it an indexing member, in the nature of a rectangular aperture through the web of end sill portions  158 ,  160  respectively, identified as respective sockets  164 ,  166  for mating engagement with one or the other of prongs  76 ,  78  of ramp  60 . Sockets  164 ,  166  are located near the distal, or outboard ends, of end sill  156 , and provide a relatively large moment arm to tend to discourage or prevent twisting of ramp  60  in the roll direction (i.e., rotation about the longitudinal axis of the rail road car) relative to deck  53 . Also, end sill  156  is a structural member capable of carrying vertical shear loads between side sills  132 ,  134  and the main sill central sill. In this way, the vertical shear load carried in prongs  76 ,  78 , during loading and unloading is reacted by end sill  156  and the supporting end structure of rail road car unit  36 . 
     Although prongs  76 ,  78  (and sockets  164 ,  166 ) are rectangular in section, it will be appreciated that a round, oval or other profile could be used. Other types of guiding and alignment members can be used rather than a sockets, such as an angle iron or C-channel forming a slide-way, provided that the mating portion on the railcar does not extend beyond the striker plates. 
     Various embodiments of the invention have now been described in detail. Since changes in and or additions to the above-described best mode may be made without departing from the nature, spirit or scope of the invention, the invention is not to be limited to those details, but only by the appended claims.