US3811383A

US3811383A - Car switching system

Info

Publication number: US3811383A
Application number: US00306487A
Authority: US
Inventors: N Butzow
Original assignee: Rexnord Inc
Current assignee: FKI Industries Inc
Priority date: 1972-11-14
Filing date: 1972-11-14
Publication date: 1974-05-21
Anticipated expiration: 1991-05-21

Abstract

A car switching system for an operator-less railway transportation system in which the track is stationary and the switching is accomplished by a mechanism mounted on the cars. This mechanism may consist of oppositely disposed cam followers mounted for vertical displacement on each side of the car and interconnected so that the cam follower or followers on one side are up, out of engagement with the track, when the cam follower or followers on the other side are down, in engagement with the track.

Description

United States Patent [191 Butzow [451 May21, 1974 CAR SWITCHING SYSTEM [75] Inventor: Neil William Butzow, Greendale,

Wis.

[73] Assigne'e: Rexnord Inc., Milwaukee, Wis.

22 Filed: Nov. 14, 1972 [21] App]. No.: 306,487

[52] US. Cl. 104/130, 246/427 [51] Int. Cl E0lb 25/06 [58] Field of Search 104/88, 96, 105, 130;

[56] References Cited UNITED STATES PATENTS 3/1972 Broome 104/130 X ll/l964 Anderson 104/88 7/l97l Marty 104/130 Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-D. W. Keen Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A car switching system for an operator-less railway transportation system in which the track is stationary and the switching is accomplished by a mechanism mounted on the cars. This mechanism may consist of oppositely disposed cam followers mounted for vertical displacement on each side of the car andinterconnected so that the cam follower or followers on one side are up, out of engagement with the track, when the cam follower or followers on the other side are down, in engagement with the track.

5 Claims, 5 Drawing Figures PATENTED HAY 2 1 mm HUI FIELD OF THE INVENTION The invention relates generally to the switching of cars from one track to another in a railway-type transportation system and, more specifically, to the switching of operator-less, remotely controlled cars in a transportation system such as is disclosed in commonly assigned U.S. Pat. Nos. 3,62l,790 and 3,650,216.

BACKGROUND OF THE INVENTION To meet the demands of some transportation systems, it is necessary or desirable to use a large number of small cars, or carriers, rather than a few large carriers, or trucks. This is particularly true where the freight to be carried by the transportation system must be sent to a large number of different destinations, but promptness is required, so that it is not feasible to accumulate to any great extent different loads going to a common destination. Such systems, moreover,may be extremely heavily trafficked, as where they are used for baggage transportation in a major airport or mail transportation in a large post office. In such situations, it is necessary that mechanisms be provided to permit rapid, highly reliable selective switching of certain cars from one transportation line to another without affecting the cars that are being sent straight through. The invention disclosed herein is such a mechanism.

SUMMARY OF THE INVENTION The moving parts of the mechanism disclosed herein for switching cars on a rail transportation system from one transportation line to another are mounted on the cars. Broadly speaking, this is opposite to the type of switching used with railroad cars, in which the moving parts of the switching mechanism are associated with the rails. The moving parts of the mechanism may consist of cam followers (1) oppositely disposed on the sides of the cars for contact with a guide which may or may not be the track itself, (2) mounted for vertical displacement, and (3) interconnected so that the cam follower or followers on one side are up, out of engagement with the guide, while the cam follower or followers on the other side are down, in engagement with the guide. The guide on one side will lead the car into one transportation line, and the guides on the other side will lead the car into the other. The cam follower or followers are spring-biased to be normally down on one side, but their disposition may be reversed by means of a movable switching ramp placed on one side of the guideway prior to each switch. A fixed switching ramp placed on the opposite side of the guideway after the switch on the transportation line into which the car is directed if the movable switching ramp has been used to reverse the disposition of the cam followers may be used to return the disposition of the cam followers to normal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a section of track including a switch.

FIG. 2 is a simplified drawing of a cross-section of a car running on the track, showing the switching mechanism.

FIG. 3 is a side view ofa fixed switching ramp as seen from the line Ill-Ill in FIG. I.

FIG. 4 is a top view of a rail having an indentation to facilitate vertical displacement of the cam followers.

FIG. 5 is a cross-sectional view of the rail shown in FIG. 4 as seen from the line V-V therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment of this invention, at each switch the approach rails 10 diverge, onerail following the'straight line, or through, track and the other following the siding. The two rails initiating at the switch are arranged according to the usual practice in railroading except for the omission of moving portions of the ordinary switch.This track arrangement is shown in FIG. 1. I

A car approaching from the left is, if if is to pass straight through, forced to its right by means described hereinafter. This has two effects. First, it allows the flanges ll of the right-hand wheels 12 to pass through the gap between the right-hand approach rail 10 and the switch rail 13 initiating adjacent thereto. Second,'it forces the left-hand wheels 15 to follow the switch rail 16 rather than the continuation of the left-hand approach rail 10. Correspondingly, if the car is to follow the siding, or branch line, it is forced to the left as it approaches the switch, allowing the flange 14 of its lefthand wheels 15 to pass through the gap between the left-hand approach rail 10 and the switch rail 16 initiating adjacent thereto and forcing the right-hand wheels 12 to follow the switch rail 13 rather than the continuation of the right-hand approach rail 10. Plates 17 are provided in the switching areas to support the flanges of the wheels as the wheels cross the gaps in the track.

The switching of the cars at each switch point may be controlled automatically in various ways. One way of controlling the switching is described in commonly assigned U.S. Pat. Nos. 3,621,790 and 3,650,2l6, and an improvement thereof will be described herein.

In the presently preferred embodiment, the means for forcing the car to the right or to the left, depending on whether it is desired to send the car straight through or direct it to the siding, include two interconnected pairs of cam followers 17 mounted, one pair to a side, on each side of the car 18. These cam followers are adapted to contact with the

guides

19 and 20, mounted for vertical displacement, and interconnected by any suitable means for insuring'that, when the'cam followers on one side are up, the cam followers on the other side are down. Thus, when a switch is encountered, the pair of cam followers which are down guide the car while the pair of cam followers which are up pass through the previously described gap in the track, taking no part in the operation.

One suitable means for interconnecting the cam followers 17 is shown in FIG. 2. It consists of guide rods 21 and 22 vertically slidable in

tubular guides

23 and 24,

arms

25 and 26,

pivot rods

27 and 28,

arms

29 and 30, drag link 31, and spring detent 32. The spring detent 32 cooperates with the end of arm 25 to hold the linkage at one end or the other of its travel.

The cars are normally conditioned to follow the lefthand branch at each switch, which may be a siding as shown in FIG. I or may be a through track if the siding is to the right. Therefore, if it is desired to send the car into the right-hand branch, the vertical disposition of the cam followers must be reversed. One suitable 3 means for accomplishing this reversal is described in commonly assigned US. Pat. Nos. 3,621,790 and 3,650,216, and another will now be described.

ln'the presently preferred embodiment, the means for reversing the vertical disposition of the cam followers consists of a movable switching ramp 33 placed on the left side of the track prior to each switch. This ramp includes a plane 34 which is normally positioned beneath the path of the left-hand cam followers 17 and means, such as an air cylinder, for pivoting the down track end'of the plane up into the path of the cam followers. If a car is to be sent into the right-hand branch at the switch, the ramp is actuated by a predetermined signal originating either from a computer or from an escort memory system such as is disclosed in commonly assigned US. Pat. Nos. 3,62l,790 and 3,650,216. When the switching ramp is actuated and acar passes the switching ramp, the cam followers on the left side of the car are forced into an up position and, by virtue of the linkage system shown in F IG. 2, the cam followers on the right side of the car are forced into a down position, causing the car to take the right-hand path in the manner previously described.

After passing the switch, the lowered cam followers 17 on the right-hand side of the car engage a fixed switching ramp 35 which forces the cam followers on that side upwardly and, acting through the linkage, lowers the cam followers on the left-hand side of the car, thereby returning the cam switching mechanism to its normal position.

While the cams '19 and are shown to cooperate with cam followers 17, the followers may be positioned to'cooperate with the adjacent rails 10, provided that the followers can be located closely adjacent the wheels and the curves inthe track are not too sharp. Otherwise it is difficult to locate the cam followers so that they will work on both a curved rail and a straight rail.

lf the cam'followers are positioned to cooperate with the adjacent rails l0,moreover, they may be subject to wedging against the side of the rail at the instant they are to be switched up or down. This wedging creates a tremendous resistance tothe displacement of the cam followers and can prevent the cam followers from moving to the desired vertical position. While the cam followersv could be made of extremely low friction material, this would be undesirable because it would allow the cam followers to slide on the rail rather than to roll- .However, it has been found that wedging may be 'prevented by running the cars on the lower flange of rails shaped like angle irons rather than on railroad-type rails and placing indentations in the upright flange of the rails where vertical displacement of the cam follower is to take place. A rail 36 having such an indentation 37 is shown in F l6. 4. When the car is in a position to start the vertical displacement of the cam followers, the rail is indented slightly, allowing the cam followers to leave the rail. The displacement is then accomplished by the switching ramp with no wedging or friction problems between the cam followers and the rail. To allow the car to travel this short distance in an unguided manner, graduated fillets 38 may be added to the rail just prior to the switching area in order to remove the normal clearance between the wheels and the rails, thus insuring that the car will be moving in a straight line along the track when it enters the unguided area. FIGS. 4 and 5 show a fillet on the same side of the rail as the indentation, but of course the fillet would be on the opposite side if the system were designed to have the wheel run on the opposite side of the rail from the side acting as the cam.

Although the specification has described only a preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes in form and detail could be made therein without departing from the inventive concept.

What is claimed is:

1. Apparatus for selectively switching from one transportation line to another a car adapted to travel in a prescribed path over the transportation lines of a system of transportation lines the individual lines in which are interconnected at switches where one transportation line diverges into two, said apparatus comprising:

indentations at the point where the vertical dis- 1 placement of the cam followers takes place in order to facilitate said vertical displacement. 2. Selective switching apparatus as claimed in claim 1 wherein said transportation lines comprise rails, said car has wheels thereon which are adapted for cooperation with said rails, and said guides are the rails on which the car travels. v v

3. Selective switching apparatus as claimed in claim 2 wherein there is normally a small amount of clearance between one side of said wheels and one side of said rails, but graduated fillets of maximum width sufficient to remove said normal clearance are provided on thesaid side of the said rails just priorto the indentations, thereby insuring that the car will be moving in a straight line along the track when it enters the area of indentations.

4. Selective switching apparatus as claimed in claim I wherein the cam followers are spring-biased to be normally down on one side and up on the other, but their disposition may be selectively reversed by means of a movable switching ramp. placed prior to each switch on the side of said rails on which the one of said cam followers which is normally down is located.

5. Selective switching apparatus asclaimed in claim 4 wherein the disposition of said cam follower is returned to normal by means of a fixed switching ramp placed on the side of the rails opposite from the side on which said movable switching ramp is placed and after the switch on the transportation line into which thecar is directed if the movable switching ramp has been used to reverse the normal disposition of the cam followers. t l i

Claims

1. Apparatus for selectively switching from one transportation line to another a car adapted to travel in a prescribed path over the transportation lines of a system of transportation lines the individual lines in which are interconnected at switches where one transportation line diverges into two, said apparatus comprising: 1. a pair of cam followers mounted one on each side of said car, said cam followers being mounted for vertical disPlacement and interconnected so that when the cam follower on one side of the car is up, the cam follower on the other side is down; and 2. a pair of stationary guides positioned to cooperate with said cam followers when in the down position only, one guide leading the car into one of said divergent transportation lines and the other guide leading the car into the other, said guides having indentations at the point where the vertical displacement of the cam followers takes place in order to facilitate said vertical displacement.

2. Selective switching apparatus as claimed in claim 1 wherein said transportation lines comprise rails, said car has wheels thereon which are adapted for cooperation with said rails, and said guides are the rails on which the car travels.

2. a pair of stationary guides positioned to cooperate with said cam followers when in the down position only, one guide leading the car into one of said divergent transportation lines and the other guide leading the car into the other, said guides having indentations at the point where the vertical displacement of the cam followers takes place in order to facilitate said vertical displacement.

3. Selective switching apparatus as claimed in claim 2 wherein there is normally a small amount of clearance between one side of said wheels and one side of said rails, but graduated fillets of maximum width sufficient to remove said normal clearance are provided on the said side of the said rails just prior to the indentations, thereby insuring that the car will be moving in a straight line along the track when it enters the area of indentations.

4. Selective switching apparatus as claimed in claim 1 wherein the cam followers are spring-biased to be normally down on one side and up on the other, but their disposition may be selectively reversed by means of a movable switching ramp placed prior to each switch on the side of said rails on which the one of said cam followers which is normally down is located.

5. Selective switching apparatus as claimed in claim 4 wherein the disposition of said cam follower is returned to normal by means of a fixed switching ramp placed on the side of the rails opposite from the side on which said movable switching ramp is placed and after the switch on the transportation line into which the car is directed if the movable switching ramp has been used to reverse the normal disposition of the cam followers.