Patent Publication Number: US-3880085-A

Title: Transportation system

Description:
United States Patent [191 Jacobs, Jr. et a].  
  1*Apr. 29, 1975 1 l TRANSPORTATION SYSTEM [76] Inventors: Justin M. Jacobs, .Ir.. 1245 Jones St.. San Francisco. Calif. 94109; Neil S. Stafford, Rt. 3. Box 355. San Jose. Calif. 95 121 l Notice: The portion of the term of this patent subsequent to May 2 1989. has been disclaimed.  
 [22] Filed: Apr. 28. 1972 2| Appl No.: 248.735  
 [53] US. Cl. 104/88; 104/121: 104/130; 104/131 I51] Int. Cl ..B6lb13/02 I53] Field of Search Mil/130. 88, 89. 93. 96&#39; 140/105. ll). 131  
 I56] References Cited UNITED STATES PATENTS 3,659,529 5/]972 Jacobs 104/121 Primary Examiner-M. Henson Wood. .lr. .4.t.\&#39;i.\&#39;ltlill livumincr-D. W. Keen AIHH&#39;IH), Agent. or Firm-Edward J. Keeling {57] ABSTRACT The disclosure is of a transportation system which includes an elongated guidebeam having three spaced apart running surfaces. Two of the running surfaces are substantially vertical to accommodate wheels rotating about vertical axes and the third running surface is substantially horizontal to accommodate wheels rotating on horizontal axes. Wheels which rotate on a vertical axis and wheels which rotate on a horizontal axis are connected to a rack which is adapted to move along the running surfaces of the guidebeam. The wheels connect the rack on the side of the guidebeam in cantilever fashion. Connecting switch sections are provided at desired locations on the elongated guideheam to connect two or more guidebeams. The switch sections have no moving Parts and cooperate with movable means. such as extendable and retractable wheels. of the rack to provide for selective high speed switching both in horizontal and vertical modes of a rack between an upline guidebeam and one or more spaced apart downline guideheams and between two or more spaced apart upline guidebeams and a single downlinc guidebeam.  
 30 Claims. 72 Drawing Figures SHEET CIGF 12 PATENTEU APR 2 9 i975 &#34;Er-3s FIG-2 PATENTEE APRZ 9 i975 SHEET DJ&#39;JF 12 PATENTEEAPRZSIQTS SHEET IUBF I2 sum 11!!! 1 1889385 PH&#39;ENTED APR29 I975 lulnllll&#39;ll Illllalll- TRANSPORTATION SYSTEM RELATED APPLICATION This application is related to our co-pending application Ser. No. 746.884 filed July 23. I968 for TRANS- PORTATION SYSTEM. The disclosure of such application is incorporated herein by reference.  
 FIELD OF THE INVENTION This invention relates to a transportation system which includes an elongated guidebeam having running surfaces for carrying a rack thereon and more specifically the invention deals with a transportation system having connecting switch sections for switching a rack between upline and downline guidebeams without the necessity of moving parts in the connecting switch sectrons.  
 BACKGROUND OF THE INVENTION A particular problem which has heretofore plagued most fixed rail and guidebeam transportation systems has occurred in switching a moving member from one fixed rail section to a record section which second section is either horizontally or vertically diverging from the main section. Heretofore. as evcmplified by conventional railroad transportation systems. it has been necessary to provide a switch section which had a movable portion between the two diverging portions of the track or running surfaces to allow switching ofthe train from one rail section to the second diverging rail section. In our above-mentioned. previously filed, copending application we disclosed a method of vertically switching a rack from an upline guidebeam to one of two downline guidebeams utilizing a movable section positioned on an intermediate connecting guidebeam switch section between the two diverging downline guidebeams. It has been found that while movable switches of this nature are operative to provide for switching a rack. it is necessary, particularly where high density. high speed flow of a number of racks is desired. that switching be accomplished without need for a movable member in the guidebeam switching section. This is particularly necessary where a computerized transportation system is desired which will allow for closely spaced. high speed travel of a number of individual racks along a guidebeam system which may include many interchanges and switches. Thus there may be many racks moving at very closely spaced intervals along a main guidebeam in such a system and it may be desirable to switch some of the racks to alternate diverging guidebeams while allowing other of the racks to pass through on the main guidebeam. The time lag required by the movable portion of the heretofore disclosed connecting guidebeam switch section requires that a definite time interval be maintained between the racks travelling on the mainline guidebeam. That is. the racks must maintain certain space intervals depending on the speed and the time lag of the switch.  
  As noted above. a unique transportation system was described and claimed in our above-mentioned. earlier filed application. As disclosed in that application, a transportation system was provided which included an elongated guidebeam having three parallel rails or running surfaces. The running surfaces included an upper guide running surface. a lower guide running surface and a support or drive wheel running surface. A rack having wheels was provided for moving on the running (ill  surfaces. The rack had load carrying means on one side and the wheels on the other side. The wheels of the rack included an upper guide wheel for running on the upper guide wheel running surface, a lower guide wheel for running on the lower guide wheel running surface and a support or drive wheel for running on the support or drive wheel running surface. The support or drive wheel was powered and moved the rack along the guidebeam. Switching means were disclosed in our earlier application. These switch means required. however. that at least some of the interconnecting running surfaces between two diverging elongated guidebeams be movable. Thus it was heretofore necessary in order to switch a rack from one elongated guidebeam [0 a second downline guidebeam to move at least some of the intermediate connecting running surfaces of the section between such guidebeams. While this operation can sometimes be handled efficiently, it has been found especially desirable to provide for high speed switching of racks from one guidebeam to a second spaced apart guidebeam. This high speed switching has been provided for by developing a rack and cooperating connecting switch sections so that it is not necessary that a portion of the connecting switch section be movable. Thus we have now developed an elongated guidebeam system which has connecting switch sections formed in a manner to cooperate with a rack so that switching of the rack from one guidebeam to another may be accomplished without the need of moving parts on the connecting switch section. In this manner high density traffic may pass to a switch section and rapidly select a path through the switch section to one or more downline guidebeams without the necessity of time delay caused by moving parts in the switch section.  
 BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to an arrangement of guidebeams interconnected by specially devised nonmovable connecting sections which cooperate with racks assembled in accordance with the invention to permit both horizontal left-right and vertical up-down switching of the racks from a main upline guidebeam to a selected guidebeam of two or more spaced apart downline guidebeams or vice versa without moving parts in the connecting guidebeam switch section. Two types of racks are disclosed in accordance with the invention. Connecting switch sections are described for eeach type of rack for switching the racks in both a horizontal mode or a vertical mode. The versatility of switching of the present transportation system is particularly helpful in providing a complete system which is compatible with a wide range of topographical and station requirements.  
  The present invention is directed to a transportation system which includes a powered rack adapted to move on a guidebeam. The guidebeam has an upper guide wheel running surface and a lower guide wheel running surface. These running surfaces are substantially vertically disposed in I80 opposing relationship with the upper guide surface formed on an interiorly facing wall of the guidebeam and the lower guide surface formed on an exteriorly facing wall of the guidebeam. A substantially horizontal support wheel running surface is also provided for on the guidebeam. A rack is provided with sets of wheels adapted to engage and to travel along the running surfaces of the guidebeam. Connecting sections are provided for connecting an upline guidebeam with two spaced apart diverging downline guidebeams to provide for selectively moving a rack to one of such downline guidebeams and connecting sections are also provided for merging two upline guidebeams into a single downline guidebeam. The connecting section has no moving parts. The rack by virtue of a movable means carried thereon may selectively be guided through the connecting section to one of either of the two or more diverging or spaced apart downline guidebeams. Thus the switch section may be embodied to connect a single upline guidebeam with two diverging downline guidebeams. The switch section may also be embodied to provide switching between a pair of spaced apart parallel mainline guidebeams. And. of course. the switch section may be embodied to connect two upline guidebeams into a single downline guidebeam. The switching may be accomplished in either a vertical or a horizontal mode.  
  The elongated guidebeam of the present invention has in general three spaced apart running surfaces provided thereon for carrying a powered rack. The rack has sets of wheels which retain the rack on the guide beam and which move on the running surfaces of the guidebeam to advance the rack along the guidebeam. More specifically the rack has sets of upper guide wheels. sets of lower guide wheels and support wheels. The sets of upper and lower guide wheels are usually made up of dual vertically spaced apart wheels although. as will be evident. other combinations of wheels or a single wheel may often be used in accordance with the invention. The running surfaces for the upper and lower guide wheels are formed in substantially vertical planes and the running surfaces for the support wheels are formed in substantially horizontal planes. The running surfaces for the upper and lower guide wheels are substantially vertical and are disposed 180 apart. The upper guide running surface is formed on an interior surface of the guidebeam while the lower guide running surface is formed on an exterior surface. Thus the guide wheels and the support wheels cooperate to hold the rack on the running surfaces of the guidebeam in cantilever fashion. Connecting switch sections are provided to connect upline guidebeams and downline guidebeams. The mainline guidebeams and the connecting switch sections are provided with upper and lower guide wheel running surfaces and sup port wheel running surfaces. The connecting switch section moreover has at least two sets of upper and lower guide wheel running surfaces. One set of upper and lower guide wheel running surfaces is connected between the mainline guidebeam and one of the spaced apart guidebeams and the other of such sets of upper and lower guide wheel running surfaces is connected between the mainline guidebeam and the other of the spaced apart guidebeams. The connecting switch guide wheel running surfaces connect the guide wheel run ning surfaces of the main guidebeam with the guide wheel running surfaces of the two separate spaced apart guidebeams. The connecting switch sections are provided with at least two horizontal running surfaces for the support wheels. The two horizontal support run ning surfaces diverge from a single support wheel running surface on a main guidebeam to the support wheel running surface of each of the two or more separate spaced apart guidebeams. The support wheels of the rack are adapted to selectively choose between one of the two or more horizontal support wheel running surfaces of the connecting switch section to determine to which one of the guidebeams that the rack will be directed. The connecting sections have no moving parts. An extendable and retractable support wheel of the rack selects one of the horizontal running surfaces of the connecting section to provide for switching the rack from one main guidebeam to a selected second main guidebeam. The guide wheels follow the appropriate guide wheel running surface to such selected second main guidebeam. Both horizontal and vertical switching of the rack are provided for by this invention.  
  Thus in one aspect the present invention is directed to a guidebeam transportation system for use by wheeled racks which guidebeam system permits switching of racks from the running surfaces of an upline guidebeam to the running surfaces of a spaced apart or diverging downline guidebeam or vice versa without the need for moving parts in the connecting guidebeam switch section. For example. an upline guidebeam is provided with appropriate horizontal and vertical running surfaces for the wheels of a rack. A connecting guidebeam switch section connects the upline guidebeam with a first diverging downline guidebeam and a second diverging downline guidebeam. The connecting guidebeam section is provided with a first set of horizontal and vertical running surfaces for each of the wheels of the rack between the running surfaces of the upline guidebeam and the running surfaces of the first downline guidebeam. The connecting guidebeam section is also provided with a second set of horizontal and vertical running surfaces between the running surfaces of the upline guidebeam and the running surfaces of the second downline guidebeam. Thus the running surfaces of the connecting switch section provide alternative diverging paths for the wheels of a rack between the upline guidebeam and the two diverging downline guidebeams. A rack having suitably arranged vertical and horizontal sets of wheels for running on such running surfaces is provided with movable means for selectively engaging either the first set or second set of running surfaces of the connecting guidebeam switch section to selectively direct the rack to the running surfaces of the selected diverging downline guidebeam. The connecting guidebeam switch sections can be embodied in a manner so that either horizontal or vertical switching of a rack from an upline guidebeam to a selected downline guidebeam is possible. The connecting switch sections have no moving parts and the mode of switching from one guidebeam to another guidebeam through the connecting guidebeam switch section is selected by movable means such as extendable and retractable support wheels of the rack. The rack utilizes sets of dual vertically spaced apart wheels for both upper and lower guide wheels to. by virtue of such vertical spacing. bridge openings in the guide wheel running surfaces that are necessary in the connecting switch section to pass portions of the rack through the section.  
  In a more specific aspect the present invention is directed to a transportation system utilizing an elongated guidebeam system. Connecting guidebeam switch sections are used to connect an upline guidebeam section with each of two or more downline guidebeams. All of the guidebeams have upper vertical guide wheel running surfaces formed on inner facing walls of the guidebeams. lower vertical guide whecl running surfaces formed on outer facing walls of the guidebeams and horizontal support wheel running surfaces formed on horizontal walls of the guidebeams. The connecting guidebeams switch section includes stationary support means extending between an upline guidebeam and each of at least two downline guidcbeams. A first horizontal support wheel running surface is provided on said stationary support means for accommodating support wheels rotating on a horizontal axis of a rack. First upper vertical guide wheel running surfaces are also located on said stationary support means to provide first upper running surfaces for the upper guide wheels of a rack. The first upper running surfaces are formed to cooperate with the vertically spaced apart upper guide wheels of the rack to permit bridging of gaps in the running surface needed to pass parts of the rack in the switch section. First lower vertical guide wheel running surfaces are provided on said stationary support means to provide first lowcr running surfaces for the lower guide wheels of the rack. The first lower running surfaces cooperate with the lower guide wheels to bridge gaps in the running surface necessary to pass parts of the rack. All of said first running surfaces serve to connect respective counterpart running surfaces of the uplinc guidebeam with the respective running surfaces of one of the downline guidehcams. A second support wheel running surface is located on the stationary support means. This second support wheel running surface diverges from the said first support wheel running surface. Second upper vertical guide wheel running surfaces are also provided on the stationary support means to provide second upper running surfaces for the upper guide wheels. The second upper running surfaces are formed to cooperate with the dual vertically spaced apart upper guide wheels of the rack to bridge gaps in this running surface which are necessary to pass parts of the rack through the switch section. Second lower vertical guide wheel running surfaces are also located on the stationary support means to provide second lower guide running surfaces for the lower dual guide wheels. The second lower running surfaces cooperate with the lower guide wheels to pass parts of the rack through gaps in the running surface which may be necessary to pass parts of the rack through the switch section. All of the second running surfaces serve to connect the respective counterpart running surfaces of the upline guidebeam with the respective running surfaces of the other of the downline guidcbeams. A rack is provided with upper guide wheels and lower guide wheels for running on the upper guide running surfaces and the lower running surfaces respectively of the guidebeams. The guide wheels are adapted to engage the running surfaces in 180 spaced apart relationship with the upper guide wheels engaging a running surface formed on inward facing walls ofthe guidebeam. In this manner the rack is held in cantilever fashion on the guidebeam. The upper and lower guide wheel sets are formed of dual wheels spaced vertically apart to bridge gaps in the respective running surfaces which are necessary in the switch section to permit passage of portions of the rack through the switch during different modes of switching. The rack also has horizontal support Wheels adapted to run on support wheel running surfaces to complete the engagement of the rack on the guidebeam. The guide wheels are arranged so that they may selectively run on either the first or the second guide wheel running surfaces of a connecting guidebeam switch section. By selectively requiring the sup- LII port wheels to run on a given support wheel running surface of the connecting switch section, the rack is selectively directed to one of the two or more downline guidebeam sections. Specially adapted vertically spaced apart upper and lower guide wheels allow the guide wheels to bridge the gaps in the guide wheel running surface which are required to pass portions of the rack during such switching operations.  
 OBJECT OF THE INVENTION A particular object of the present invention is to provide a transportation system for carrying people. freight and vehicles over a minimum right of way which transportation system includes an elongated guidebeam system havine nonmoving switch sections for carrying a special rack at high speeds and which provides for switching the rack in both horizontal and vertical directions both diverging from an upline guidebeam to one of two or more downline guidebeams and merging to a downline guidebeam from two or more spaced apart upline guidebeams without the use of moving parts in the connecting switch section.  
 BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of the present invention will become apparent from the following detailed description read in light of the accompanying drawings which are made a part of this specification and in which FIG. I is a perspective schematic illustration of the modes of switching that are selectively accomplished in accordance with the preferred embodiment of apparatus of the present invention without the use of moving parts in the connecting switch sections:  
  FIG. 2 is a side elevation in schematic form of the preferred embodiment of apparatus assembled in accordance with the present invention;  
  FIG. 3 is an end elevation in schematic form of the preferred embodiment of apparatus assembled in accordance with the present invention;  
  FIG. 4 is a detailed elevation view with portions broken away for clarity of presentation of the preferred rack assembled in accordance with the present invention;  
  FIG. 5 is a detailed side elevation with portions broken away for clarity of presentation of the preferred rack assembled in accordance with the present invention;  
  FIG. 6 is a bottom view with portions broken away for clarity of presentation of the preferred rack assembled in accordance with the present invention:  
  FIG. 7 is an enlarged sectional view with parts removed for clarity of presentation taken at line 77 of FIG. 6 and illustrates the apparatus used to drive the support wheel;  
  FIG. 8 is a sectional view with parts removed for clar ity of presentation taken at line 88 of FIG. 7 and illustrates the apparatus used to drive the support wheel;  
  FIG. 9 is an enlarged sectional view with parts removed for clarity of presentation taken at line 9-9 of FIG. 4 illustrating apparatus for extending and retracting the support wheeL and showing the support wheel in retracted position;  
  FIG. I0 is an enlarged sectional view similar to FIG. 9 illustrating the support wheel in extended position;  
  FIG. I1 is an elevation view of a portion of apparatus illustrated in FIGS. 9 and I0.  
  FIG. I2 is a side elevation view of a connecting switch section providing vertical switching in accordance with the preferred form of the present invention;  
  FIGS. I2ul2i are sectional views taken as indicated from FIG. 12;  
  FIG. 13 is a side elevation view of a connecting switch section providing horizontal switching in accor dance with the preferred embodiment of apparatus assembled in accordance with the present invention;  
  FIGS. 1311-13 are sectional views taken as indicated from FIG. 13.  
  FIG. 14 is a partial top view ofthe connecting switch section shown in FIG. I3;  
  FIGS. 140-14!) are sectional views taken as indicated from FIG. I4;  
  FIG. I5 is a side elevation view of the first portion of a vertical switch connecting section providing interchange between two main guidebeams for the preferred embodiment of apparatus assembled in accordance with the present invention;  
  FIGS. ISu-lSfare sectional views taken as indicated from FIG.  
  FIG. I6 is a side elevation view of the second portion of the connecting section of FIG. 15 illustrating vertical interchange between two main guidebeam sections for the preferred embodiment of apparatus assembled in accordance with the present invention:  
  FIGS. I6u-l6e are sectional views taken as indicated from FIG. I6.  
  FIG. 17 is a perspective schematic illustration of the modes of switching that are selectively done by the alternative embodiment of apparatus of the present invention without the use of moving parts in the connecting switch section;  
  FIG. 18 is a schematic side elevation of an alternative embodiment of apparatus assembled in accordance with the present invention.  
  FIG. 19 is a schematic end elevation of the alternative embodiment of apparatus assembled in accordance with the present invention;  
  FIG. 20 is a detailed elevation view of an alternative rack assembled in accordance with the present invention;  
  FIG. 21 is a detailed end elevation view of the alternative rack assembled in accordance with the present invention.  
  FIG. 22 is a detailed top view of the alternative rack assembled in accordance with the present invention;  
  FIG. 23 is a side elevation view of an alternative connecting guidebeam switch section useful to switch an alternative rack selectively between two vertically spaced apart guidebeam sections;  
  FIGS. 230-231 are sectional views taken as indicated from FIG. 23;  
  FIG. 24 is a side elevation view of an alternative embodiment of connecting switch section providing for horizontal switching of an alternative rack between a first guidebeam section and two diverging downline guidebeam sections;  
  FIGS. 24a-24g are sectional views taken as indicated from FIG. 24:  
  FIG. 25 is a top view of a portion of the connecting switch section illustrated in FIG. 24&#39;. and  
  FIGS. 25u-25b are sectional views taken as indicated from FIG. 25.  
 DETAILED DESCRIPTION OF PREFERRED EMBODIMENT In the drawings. FIG. I shows a perspective schematic illustration of the modes of switching that may be selectively accomplished in accordance with the preferred embodiment of apparatus of the present invention. These modes of switching are accomplished without the use of moving parts in the connecting switch section. Thus in accordance with the invention a rack may switch horizontally from a main guidebeam to the left or to the right. to diverging downline guidcbeams. or may continue through such a connecting switch section on the mainline guidebeam. As is evident by the reverse arrows, the switch section can be modified so that a rack may also be switched into a through mainline guidebeam from guidebeams merging from the left or the right. The rack may be switched from a mainline guidebeam vertically up or vertically down to vertically diverging guidebeams or may be directed through such a switch section on the mainline guidebeams. Switching may be done between two vertically spaced apart mainline guidebeams with through travel also provided on both guidebeams. As again indicated by the reverse arrows the switch section may be embodied to permit vertical switching from two spaced apart guidebeams to a single mainline guidebeam. Many combinations of switching are provided in accordance with the present invention. FIG. I is used to illustrate some of the modes of switching in accordance with the invention.  
  Refer now to FIGS. 2 and 3 in particular where the preferred embodiment of apparatus assembled in accordance with the present invention is shown in schematic form. FIG. 2 is a side elevation and FIG. 3 is an end elevation partially in section showing a rack generally indicated by the number 20 attached to and in running position on an elongated guidebeam which is generally indicated by the number 30. The guidebeam is formed to provide a path in the transportation system and serves to carry the running surfaces on which the rack 20 moves. The rack 20 is comprised of frame member 22 having a series of spaced apart wheels rotatably attached thereto. The wheels include sets of upper guide wheels 33. 35; sets of lower guide wheels 37. 39; and support wheels 38. The support wheels 38. as hereinafter will be discussed in detail. are usually driven by a power source and therefore also function as drive wheels to move the rack along the guidebeam. As indicated in the drawings. the preferred embodiment rack has sets of dual vertically spaced apart upper guide wheels which include wheels 33 and 35. These wheels form a set of upper guide wheels. The lower guide wheels comprise a pair of vertically spaced apart wheels 37 and 39. The sets of wheels are positioned on the frame 22 at suitable intervals depending on the load and length of the rack 20. It is usually desirable to have at least two sets of dual upper guide wheels. two sets of dual lower guide wheels. and at least two support wheels.  
  The guidebeam 30 is held in desired position by suit able support means. such as for example. by a series of columns. such as column 44, spaced apart along the right of way. The guidebeam 30 may be composed. for  
 example. of prestressed sections resting end to end on I a series of supports such as column 44. Suitable overall dimensions for such prestressed sections as a guide to understanding the present invention have been found to be about 8 feet high by (w feet wide and 100 feet long. The guidebeam may be formed as illustrated in&#39;FlGS. 2 and 3 so that racks can utilize both sides of the guidebeam. In this manner racks travelling in opposite directions may utilize the same guidebeam at the same time.  
  The guidebeam 30 provides at least three spaced apart running surfaces for the rack. Thus on each mainline right of way portion of the guidebeam there is provided an upper guide running surface 34&#39;. a lower guide running surface 40; and a support wheel running surface 42. The upper guide running surface 34 and the lower guide running surface 40 ha\ e substantially vertically disposed running surfaces to accommodate the upper and lower guide wheels respectively. The upper guide running surface 34 is formed on an inner wall of the guidebeam. The lower guide running surface 40 is formed on an outer facing wall of the guidebeam. The support wheel running surface is disposed in a substantially horizontal plane to accommodate the support wheels. As illustrated in FIGS. 2 and 3. the selfpowered rack is adapted to be held and to be moved on the three running surfaces of the guidebeam in cantilever fashion. Thus the upper guide surface 34 is formed on an inward facing wall of the guidebeam while the lower guide running surface 40 is formed on an outward facing wall of the guidebeam 30. The upper guide wheels 33. 35 and the lower guide wheels 37, 39 cooperate with the support wheels 38 to position the rack on the running surfaces of the guidebeam in canti lever fashion.  
  The dual wheel configuration of the upper guide wheels 33. 35 and the lower guide wheels 37. 39 is provided to permit the rack to he switched from an upline guidebeam to one of two or more spaced apart downline guideheams or vice versa without the need for moving parts in the connecting guidebeam switch section. The present invention provides for such switching of a rack 20 from the main upline guidebeam section to one of two or more downline guideheams or vice versa. in either a vertical or horizontal mode. The dual guide wheel configuration ofthe upper and lower guide wheels permits continuous contact of one or the other of the respective dual upper and lower wheels with their respective guide running surfaces during the entire switching operation as the rack is switched from one guidebeam to another through the switch section. Since. as is fully explained later. it is necessary to have gaps in the guide running surfaces of the connecting switch guidebeam sections to permit passage of portions of the rack on different paths through such switch sections it is preferred to have dual guide wheels on both upper and lower guide wheels so that one of the dual wheels on each guide wheel is always in contact with its respective running surface. The dual upper and the dual lower guide wheels are necessary so that the same rack may utilize all of the various vertical and horizontal switch sections hereinafter described. It will be apparent that for some switches a dual configuration of both upper and lower guide wheels may not be necessary. As indicated in FIG. 2 and FIG. 3. the mainline sections of the guidebeam preferably only provide a running surface for one of the wheels of each of the upper guide wheels and the lower guide wheels. Thus it is desirable that only one upper and one lower guide wheel engage a running surface on a mainline section of the guidebeam system. However. it is of course possible to have mainline guideheams which provide running surfaces for all the guide wheels.  
  The rack 20 is driven along the guidebeam means by a suitable power source supplying power to the support wheel 38. As noted it is preferred to use a wheel which rotates on a horizontal axis as the drive wheel. It is of course possible to provide either or both the upper guide wheels and the lower guide wheels with power. Motive power is supplied to the support wheel 38 by a suitable power source. Such a power source may be for example an electric motor or an internal combustion engine. Such a power source is schematically illustrated in FIG. 2 by the box indicated by the number 46. If it is desirable to drive more than one support wheel then a second power source 48 may be utilized. Suitable drive train means are provided to connect the power source 46 to the support wheel 38. Control means are preferably carried on the rack 20 to control the power sources 46 and 48 and the movement of rack 20 along the guidebeam 30. Control means 50 is preferably electrically activated and in many instances will be tied into a computer network so that a number of racks may be moved at closely spaced intervals along the guidebeam.  
  Refer now to FIGS. 4. 5 and 6. FIG. 4 is an elevation view of the preferred rack assembled in accordance with the present invention. FIG. 5 is a side elevation view of the preferred rack and FIG. 6 is a top view of the preferred rack of the present invention. The rack has two sets of dual upper guide wheels 33, 35 and two set of dual lower guide wheels 37. 39. Support or power wheels 38 are used to move the rack 20 along the running surfaces of the guidebeam. The rack 20 includes a frame 22 which has overhanging arm members 62 which are adapted to extend over the upper portion of the guidebeam to cause the upper guide wheels to engage the inner running surface of the guidebeam which forms the upper guide wheel running surface. The support wheel 38 and the lower dual guide wheels 37. 39 are preferably formed in units and connected to the frame 22 mating flanges and 94. In accordance with the invention the rack has a movable means which cooperates with the diverging or converging running surfaces of a connecting switch section to provide for directing the rack from a main upline guidebeam to one of two or more diverging downline guideheams or vice versa. Certain wheels of the rack are useful as such a movable means. Thus the support wheels 38 0f the preverred apparatus are extendahle and retractable to direct the rack through a selected diverging or converging running surface of a connecting switch section.  
  The support wheels 38 are extended and retracted from the rack by suitable means as illustrated schematically in FIGS. 4-6. The wheels 38 are preferably extended or retracted in a direction normal to the direction of travel of the rack while the rack is moving along the guidebeam to reduce friction caused by such movement. Such friction is reduced to an acceptable minimum when rubber pneumatic tires are used. The axles 32 of the support wheels 38 are rotatably mounted on the frame 22 of the rack 20. In addition. these rotatably mounted axles 32 are also prepared so as to be capable of reciprocal motion. i.e.. they can move in and out from the rack. Suitable bell cranks 107 are pivotably mounted on pins I08. One of the ends 99 of each of the bell cranks is connected to the ends of the axles. The other ends 109 of the bell cranks are connected to a suitably arranged double acting hydraulic cylinder I05 through push rods I06. The hydraulic cylinder I05 is fixedly mounted in the frame 22 by suitable pins 98 which engage in the frame. Thus. when the hydraulic cylinder is activated the support wheels 38 are extended or retracted by the action of the above described mechanical linkage. Hydraulic fluid for the hydraulic cylinder is provided by hydraulic motor 97 which is controlled by control means 50 through suitable connections as shown. Although two positions of the support wheel are disclosed in the preferred embodiment. it is evident that the support wheel may be extended and retracted to operate on three or more running surfaces by suitable action of the hydraulic cylinder 105. The support wheels 38 are powered through axles 32 by appropriate power sources. The power source may be formed by an electric motor or internal combustion engine. Thus electric motors 96 are connected through suitable drive train linkage to the drive wheels 38 through axles 32. The powered support wheel 38 is preferably arranged for rotation about a horizontal axis and disposed to run on a surface located immediately above the lower of the dual lower guide wheels 39. The support wheel 38 power source is con trolled by control means 50 carried on the frame 22. Suitable circuitry extends between the control means 50 and motors 96 for providing control. As described in our above-cited. co-pending application, suitable electrical rails may be provided on the guidebeams for pickup by a shoe carried on the rack to supply electricity to the rack.  
  Arranged on the load carrying side of the rack are a series of load hook means generally indicated by the number 81. The load hooks 81 are pivotly mounted on a shaft 83. The load hook 8I is controlled and pivoted by suitable linkage 84. The linkage 84 is connected to a hydraulic cylinder 85 which extends or retracts the hook 8L Motor 86 controls the extension and retraction of the cylinder 85. Thus. when a load is moved against the rack 20 the load hooks 81 are activated to secure the load to the rack by engaging suitable rings on the load. The load may be released by actuating the load hook 81 through the linkage 84. A locking arm 87 which is pivotly mounted on the frame is provided for use in locking hook 8| by means of switch 88 to prevent aecidental movement of the book.  
  The upper and lower dual guide wheels are vertically spaced apart on the frame member. The distance which is required between the top wheel 33 and the bottom wheel 35 of a set of upper dual guide wheels will vary depending on a number of considerations. These considerations will become apparent when the nonmoving switch sections are described later in detail. The distance that the top wheel 33 is located above arm 62 is also governed by a number of considerations. It is noted that the center of the top wheel is about two times farther from the center of the arm 62 than the center of the bottom wheel 35 of the upper dual guide wheelsv This arrangement is necessary so that the support arm 62 may be allowed to pass through gaps in the running surface of the switch sections while maintaining one of the two upper guide wheels 33, 35 on the upper guide running surface. Similarly the lower guide wheels 37, 39 are vertically spaced apart to provide for bridging gaps in the running surfaces ofthe connecting switch section needed to pass the portions of the arm 62 and the support wheel axel 32 extending into the guidcbeams.  
  FIGS. 7 through ll illustrate the extendable and retractable support wheel and the means for driving the support wheel of the present invention which permits switching of a rack without moving parts on the switch. FIG. 7 is an enlarged sectional view taken at line 7-7 of FIG. 4 with parts removed for clarity of presentation illustrating the assembly of apparatus used to rotate the support wheel of the rackv FIG. 8 is a sectional view taken at line 8-8 of FIG. 7 with parts removed for clarity of presentation and also illustrates the drive means for the support wheel. Referring specifically now to FIGS. 7 and 8, a support wheel 38 is rotatably connected to the frame 22 ofa rack. An axle 65 having a suitable flange 66 is connected to the support wheel by suitable bolts and the axle extends through housing 67 into the interior of the frame 22. A sleeve bearing member 68 supports the axle 65 inside of housing 67. This bearing member 68 is adapted to allow both rotating movement and reciprocal movement of the axle 65. The interior end portion of the axle is splined. The splined end 69 of the axle is captured in a bearing housing 70 and as will be further described below, the ball hearings in housing 70 are arranged in a manner to per mit reciprocal. i.e.. longitudinal stroking motion of the axle and to permit rotational motion of the axle within the housing 70. Thus when the housing 70 is rotated the axle 65 is also caused to be rotated. The ball bearing housing 70 is rotatably mounted in the frame 22 on suitable supports 71-74 by sleeve bearing member 75. A main gear member 76 is located around ball bearing housing 70 and is fixedly connected for rotation therewith by suitable means such as a key 77. Thus when the gear member 76 is rotated. the axle 65 is caused to to tate which in turn rotates support wheel 38 which moves the rack. A worm gear 78 is mated to the main gear member 76. The worm gear is mated to the main gear member 76. The worm gear is rotatably mounted on the frame 22 by sleeve bearings I10. III. A shaft of the worm gear extends into motor 96. When the motor operates to drive the shaft the power is transmitted to the support wheel as described above.  
  The means for extending and retracting the support wheel are illustrated in detailed FIGS. 9-1 I. FIG. 9 is an enlarged sectional view with parts removed for clarity of presentation taken at line 9-9 of FIG. 4 and shows the support wheel 38 in retracted position. FIG. [0 is an enlarged sectional view similar to FIG. 9 and shows the support wheel in extended position. The power and driving mechanisms shown in detail in FIGS. 7 and 8 have been substantially removed from FIGS. 9 and 10 to allow for clarity of presentation. FIG. I1 is an elevation view of the bell crank and shows the yoke portion thereof.  
  As noted above. the axle 65 which carries the support wheel 38 enters the frame 22 through housing 67. A sleeve bearing member 68 rotatably and reciprocally mounts the axle in the housing. The other end 69 of the axle is splined and is constrained in bearing housing 70. The splines of the axle are captured between longitudinal rows of ball bearings 112 which in turn are held against rotation by ribs 113 of bearing housing 70.  
  The extension and retraction of the support wheel is accomplished by stroking the axle 69 in or out as desired. Thus the support wheel is stroked in a direction normal to the direction of travel of the rack to select a running surface on which it moves. A flanged collar 114 is fixedly connected to the axle 65 and rotates therewith. A bell crank I07 having a yoke I15 at one end is adapted to engage pins 116. II7 into the collar I14. These pins H6. 117 allow the collar to rotate. However. as the pins are moved back and forth by the action of the bell crank 107 they cause the collar to estend and retract the support wheel 38 to the positions illustrated in FIGS. 9 and III. The bell crank is rotatably mounted by means of pivot pin I08 on arm 118 of the frame. One end of a push rod I06 is connected to the end 99 of the bell crank I07. The other end of the push rod I06 is connected to a hydraulic cylinder [05 which is used to move the bell crank and to thus extend and retract the support wheel 38. A spring I19 is useful to assist in retracting the support wheel is desired. Additionally the spring 1]) serves to move the support wheel to a retracted position should the linkage from the hydraulic cylinder fall.  
  In accordance with the present invention two positions are provided for the support wheels. That is to say that it has been found that when the support wheel is capable of being moved to two separate horizontal running surfaces that switching can be accomplished without the use of movable parts in the connecting switch section. In accordance with the invention then the rack is switched or is caused to continue along a given guidebeam depending on the running surface which the extcndable and retractable support wheel elects to follow in the upstream portion of the connecting guidebeam section. A support wheel of the present invention is thus movable to at least two possible positions in a direction normal to the direction of rack travel. It will be apparent that the above discussed linkage can be moditied to provide for three or more positions for the support wheel if such is desirable for any given switch configuration. In the first position. for example, the support wheel will follow a running surface which will permit a rack to continue along the main guidebeam right of way. In a second position the support wheel will cause a rack to be switched vertically or horizontally to an auxiliary guidebeam right of way by virtue of the support wheel following a support wheel running surface which causes the rack to be so switched.  
  FIGS. I2 through FIG. 16 illustrate a number of connecting switch sections arranged in accordance with the preferred embodiment of apparatus assembled in accordance with the present invention. These connecting switch sections afford various switching modes both in a vertical manner and in a horizontal manner for the preferred rack of the present invention. The preferred rack as set out above is of the type having a support wheel disposed well below the center of gravity of the rack. The vertical and horizontal modes of switching refer to the overall disposition of the rack through the connecting switch section. Thus when referring to a horizontal switch section it is understood that while there may be some vertical displacement of the rack going through the section. the switching operation is carried out primarily at a constant elevation. Vertical switch sections on the other hand require substantial displacement of the rack to achieve switching. It will also be evident that while many of the switch sections are described as proceeding from an upline guidebeam to one of two or more selected downline guidebeams. the opposite can also occur. That is. by reversing direction of travel of the rack and the sequence of stroking fill of the support wheel (or by reversing the elements of the connecting section) a rack may come from one of two spaced apart guidebeams through a connecting switch section to merge with a single mainline guidebeam.  
  In FIG. 12 and FIGS. IZu-lZi a vertical connecting switch section is illustrated. In this vertical switch section provision is made for selectively directing a rack from an upline guidebeam to one of two or more vertically spaced apart downline guidebeams. It is noted that one of the downline guidebeams forms essentially a through track with the upline guidebeam and therefore this switch section may. if desired. be aptly described as selectively permitting a rack to continue along on a mainline guidebeam or alternatively be vertically switched to an alternative vertically displaced downline guidebeam. As noted, if this switch section were set up for travel in the opposite direction. merging into a single guidebeam would occur. FIG. I3. FIGS. Illa-Hg. FIG. l4 and FIGS. l4u-l4h illustrate a horizontal switch connecting section for the preferred rack which provides for substantially horizontal switching of racks between an upline guidebeam and two or more spaced apart downline guidebeams. Here also it is obviously possible to think of selectively causing the rack to continue along a main guidebeam (both upline and downline of the switch section) or to he directed to a diverging downline guidebeam. FIG. 15. FIGS. lSu-lSf. FIG. l6 and FIGS. l6u-l6e show a vertical switch connecting section for selectively moving racks between two vertically spaced apart parallel mainline guidebeams. It is noted that while the embodiment of FIG. 15 and FIG. 16 provide a connecting switch section for selectively either directing a rack through the switch section to cause it to continue along the lower mainline or upper mainline or directing a rack from the lower mainline to the upper mainline that obviously the switch can be embodied to switch the rack from the upper mainline to the lower mainline in accordance with the invention. It is also noted that FIG. l5 and FIG. I6 illustrate both diverging switching and merging switching in the same switch section.  
  Thus in summary. FIGS. 12-16 inclusive illustrate various connecting switch sections for switching the preferred rack of the present invention in both a horizontal mode and a vertical mode. These connecting switch sections are all compatible with the preferred rack and thus a transportation system utilizing the preferred guidebeam construction may incorporate either or both horizontal switches and vertical switches at various places to be utilized by a single type of rack. Thus at one place because ofspace limitation it may be desirable to incorporate a vertical switch into the system while at another place a horizontal switch may be preferable and as further noted. the switch sections may be used to provide connection from an upline mainline guidebeam to one of two diverging downline guidebeams and in addition to provide merging to a single downline guidebeam from two upline guidebeams.  
  In order to specifically describe the various switch sections. first refer to FIG. I2 and FIGS. l2al2i where a vertical connecting switch section of guidebeam is illustrated. This connecting switch section is used to vertically switch racks between an upline guidebeam and one of two downline guidebeams for continued travel along a selected route of the system. FIG. [2 is an elevation view and FIGS. Ila-l2! are sectional views