BACKGROUND OF THE INVENTION This invention relates generally to the field of connectors, and more particularly to connectors which may be coupled and uncoupled by hand or which may be uncoupled by pulling apart the connectors with a prescribed force. In one specific application, the invention relates to connectors which may be used to connect air lines and/or electrical signal and power lines for a rail car braking system.

Current braking systems used on most freight trains in the United States are based on a technology that was developed almost one hundred years ago. Such systems rely on the use of pressurized air to both control and power the brakes. In order to supply pressurized air to the rail cars, an air line is provided along each rail car. When the rail cars are connected, each air line is coupled together to form a single air line running the length of the train. The coupling mechanism generally employed to join each air line is commonly referred to as a "gladhand" coupling and has remained substantially unchanged over the last century.

To connect a pair of gladhand couplings, the couplings are abutted adjacent each other and the couplings are rotated in opposite directions until sufficiently engaged. The gladhand couplings each contain a 90 degree bend through which air must travel when passing through the connection. To prevent the couplings from disconnecting when subjected to vibration, some have incorporated a locking device which locks the couplings together after they have been joined.

Although gladhand couplings have been generally successful in coupling air lines of conventional pneumatic braking systems, such systems suffer from significant drawbacks which have prompted the development of newer systems. More particularly, with such pneumatic systems braking time is

affected by the speed with which air pressure changes travel along the train. For trains having large numbers of rail cars, a significant delay may be experienced while the compressed air passes the entire length of the train. To compensate for this delay, trains require a longer stopping time and may also be prematurely or overly slowed in order to ensure a safe operating speed.

Recently, a new braking system has been proposed and is referred to as an Electrically-Controlled-Pneumatic (ECP) braking system. The ECP braking system relies on air to power the brakes, but controls actuation of the brakes electronically. Hence, to operate the ECP braking system, each rail car must be provided not only with compressed air but also with an electrical power or signal line. Gladhand couplings are ill- suited for connecting both air and electrical lines since the gladhand couplings are rotated to join the couplings.

One pair of connectors suitable for use with the ECP braking system is described in co-pending U.S. Application Serial No. 08/548,993, filed October 27, 1995, the complete disclosure of which is herein incorporated by reference.

Although workable, it would be desirable to provide various improvements to such connectors. In particular it would be desirable to produce a connector which is less complicated and includes fewer parts. It would further be desirable if such connectors could be joined simply by pushing the two connectors together, rather than employing a secondary operation such as twisting a coupling nut on each of the connectors.

Hence, it would be desirable to provide connectors which may easily be coupled and uncoupled, particularly by hand. It would further be desirable if such connectors could be axially pulled apart at a prescribed force such as when two rail cars are disconnected. It would be still further desirable if such connectors would remain connected once subjected to significant vibration. Such connectors should also be hermaphroditic so one connector may be interchangeably connected with any other connector.

SUMMARY OF THE INVENTION The invention provides an exemplary connector which may be connected to another substantially identical connector to form a connector system. The connectors of the invention may be coupled together by merely pressing the connectors together until they interlock. In this way, no rotation of the connectors is required in order to couple the connectors.

The connector system comprises a first and a second connector, with each connector having a connector body. Each connector further includes a latch arm pivotally connected to one side of the connector body so that the latch arm is generally aligned with the connector body. A latch bolt is rotatably attached to another side of the connector body generally opposite the latch arm. A biasing member is positioned between each latch arm and each connector body to control the amount of force required to pivot the latch arms away from alignment with the connector body. In this manner, the first and second connectors may be connected by abutting the connector bodies so that the latch arms are received over and interlock with the latch bolts on the abutting connector.

Each latch arm will usually include a tooth at a distal end, and each latch bolt will preferably be cylindrical and have a planar face. With such a configuration, the latch bolts rotate as the teeth slide over the faces. After the teeth have completely passed over the faces, they become interlocked with the latch bolts to secure the connectors together. Once securely connected, the connectors may be disconnected in one of two ways. First, the connectors may be manually disconnected by including a lever on each latch bolt. The lever may be torqued to rotate the bolts and allow the teeth to slide over the faces. In the second alternative, the connectors may be axially pulled apart, with the biasing member being employed to control the amount of force required to pull the two connectors apart. More specifically, as the connectors are pulled axially away from each other, the biasing member compresses to allow the latch arms to move out of their aligned position so that the teeth may

slide over the latch bolts. When the connectors are used to connect air and/or electrical lines for rail cars, the connectors will preferably remain joined until pulled apart with a force that is greater than about two hundred pounds per square inch.

In one exemplary configuration, the connectors will be used to join air and/or electrical lines of rail cars. In such an embodiment, each connector will preferably include a central lumen extending therethrough. An air hose is connected to each connector body so that the air hoses are aligned with the central lumen. The connector bodies will preferably each include a resilient gasket that is aligned with the central lumen. In this way, a seal is formed between the two lumens upon connection of the connector bodies. The resilience in the gasket allows for a wide variation in the gap between the two connectors while still providing a sufficient seal between the air lines.

Each connector will preferably further include a signal contact. The signal contacts will be disposed on the connector such that they may be joined together upon connection of the connector. The signal contacts employed by the invention may include a variety of different contacts including electrical contacts, fiber-optic contacts, and the like. In the case of rail cars, the contacts will preferably be electrical so that they may be used in connection with an electrically controlled pneumatic (ECP) braking system.

In another exemplary aspect, each connector will preferably be substantially identical to the other connector. Such construction is particularly useful with rail cars which may have either of its two ends connected to another rail car. In another exemplary aspect, each connector will preferably include at least one alignment pin which aligns the connector bodies during connection. The alignment pin further helps keep the connector faces from sliding sideways when the connectors are mated and unmated. Specifically, when the connectors are uncoupled by pulling them apart, such as when train cars

uncouple, the latch arms exert a force on the connector which tends to make the connector faces slide sideways, across each other. The alignment pin helps prevent such sliding and therefor protects the electrical contacts. The invention further provides an exemplary method for coupling a pair of connectors. According to the method, a first and second connector are provided, with each connector having a connector body with a central lumen extending therethrough. A latch arm is pivotally connected to one side of each connector body so that the latch arm is generally aligned with the connector body. A latch bolt is rotatably attached to another side of-each connector body, generally opposite the latch arm. A biasing member is further provided and is positioned between each latch arm and each connector body to control the amount of force required to pivot the latch arms away from alignment with the connector body. To join the connectors, the connector bodies are abutted so that the latch arms are received over and interlock with the latch bolts on the abutting connector. In one exemplary aspect, each latch arm will preferably include a tooth, and each latch bolt will be cylindrical and have a planer face. The latch bolt will preferably have its rotation controlled by a torsion spring so that as the teeth slide over the faces, the bolts will rotate until the teeth pass over the faces. At this point, the bolts will rotate in an opposite direction (due to the torsion spring) to allow the teeth to interlock with the latch bolts and secure the connectors together.

In another step of the method, compressed air is passed through the lumens after the connectors are coupled. In a further aspect, a signal contact is provided on each connector. The signal contacts are joined upon connection of the connectors so that a signal may be passed through the contacts. Preferably, an electrical signal will be passed through the contacts, such as with an ECP braking system.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of an exemplary connector according to the present invention.

Fig. 2 is a top view of a pair of connectors joined together according to the present invention.

Fig. 3 is a side view of the connectors of Fig. 2. Fig. 4 is a cross sectional side view of the connectors of Fig. 2.

Fig. 5 is a side view of a latch arm of the connector of Fig. 1.

Fig. 6 is a side view of a latch bolt of the connector of Fig. 1.

Fig. 7 is a side view of the latch bolt of Fig. 6 rotated ninety degrees. Figs. 8-10 illustrate cooperation of the latch arm and the latch bolt in joining a pair of connectors according to the present invention.

Fig. 11 is a cut-away view of the connectors of Fig. 2 showing a pair of electrical contacts.

DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The invention provides methods, systems, and apparatus for coupling various lines such as air lines, electrical lines, fiber-optic lines, and the like. The methods, systems, and apparatus allow for such lines to be easily coupled and uncoupled by hand. In addition, such lines may be uncoupled by axially pulling apart the lines to separate the lines at a prescribed force without damage to the lines. The connection between the lines is sufficiently stable so that lines will not become disconnected, even when subjected to significant vibration. Although the methods, systems, and apparatus may be employed to connect a variety of lines, they will find their greatest use in connecting air and electrical lines used in conventional pneumatic or in electrically-controlled-pneumatic (ECP) braking systems employed by the railroad industry. For convenience of discussion, the connectors of the present

invention will be described with reference to freight trains employing ECP braking systems. However, it will be understood that the invention may be useful in a variety of other applications. Referring to Fig. 1, an exemplary embodiment of a connector 10 will be described. Connector 10 comprises a connector body 12 having a proximal end 14 and a distal end 16. An axial lumen 18 extends between proximal end 14 and distal end 16. Pivotally attached to connector body 12 is a latch arm 20. Latch arm 20 is generally aligned with the connector body 12 and is attached such that latch arm 20 will resist movement away from its aligned orientation as described in greater detail herein after. Generally opposite of latch arm 20 is a latch bolt 22. Latch bolt 22 is rotatably connected to connector body 12 so that latch bolt 22 may be rotated about its central axis. Connector body 12 is provided with a slot 24 having a geometry which will mate with a latch arm of an adjoining connector. Latch bolt 22 passes through slot 24 to enable the latch arm to interlock therewith. Proximal end 14 is configured to receive a length of tubing, a hose, or the like which supplies compressed air to the train's brakes. Proximal end 14 may alternatively be threaded or otherwise configured to accommodate a mechanical connection. In this manner, compressed air passing through the length of tubing will in turn pass through axial lumen 18 and to an adjoining connector.

Distal end 16 includes a resilient gasket 26. Gasket 26 will mate a corresponding gasket from another connector when attached thereto. As the connectors are drawn together, gasket 26 forms a seal between the connectors to prevent escape of compressed air between the connectors. Gasket 26 is preferably constructed of an elastomeric material, thereby allowing for a wide variation in the gap between mated connectors while still providing an airtight seal. Attached to connector body 12 by a bolt 28 is an electrical conductor 30 having a pair of electrical contacts 32,

34. When connector 10 is mated with another connector, electrical contacts 32, 34 are in turn joined with mating electrical contacts on the adjoining connector so that power and/or signals may be passed through conductor 30. This allows power or electrical signals to be passed car to car when the connectors are engaged. Although shown as an electrical conductor, other signal carrying devices may optionally be used, such as fiber-optics or other conductors capable of carrying signals. At distal end 16, connector body 12 includes a variety of steps 36, 38 and 40. Steps 36, 38 and 40 serve as alignment steps and will engage corresponding steps of a mating connector. The alignment steps perform two functions. First, the alignment steps assist in aligning two connectors as they are joined together. Secondly, the alignment steps keep the connector faces from sliding sideways when the connectors are mated and unmated. For example, when connectors are uncoupled by pulling them straight apart, such as when train cars uncouple, the connectors will tend to slide sideways relative to each other. If such sliding were allowed, electrical contacts 32 and 34 would be torn apart.

Referring now to Figs. 2 and 3, the mating of two connectors 10 will be described. The connectors 10 are hermaphroditic, i.e. essentially identical to each other. For convenience of discussion, the same reference numerals will be employed to describe both connectors. As best shown in Fig. 3, latch arm 20 is received into slot 24 where latch arm 20 interlocks with latch bolt 28. Alignment steps 36 face each other an align the connectors during connection as previously described. Latch arm 20 further assists in aligning the connectors when mated. When mated, electrical contact 34 is joined with an electrical contact 32 of the opposite connector.

Latch bolts 28 further include a lever arm 42 which allows the connectors to be manually separated as bolts 28 are rotated by torquing lever arm 42 as described in greater detail hereinafter.

Referring now to Fig. 4, attachment of latch arms 20 and latch bolts 22 to connector body 12 will be described in greater detail. Latch arms 20 are pivotally attached to connector body 12 by a pivot pin 44. A spring 46 is attached to a head 48 which in turn is in contact with a proximal end 50 of latch arm 20. Spring 46 tends to push proximal end 50 away from connector body 12. A stop 52 prevents proximal end 50 from moving out of alignment with connector body 12 therefor maintaining the aligned orientation of latch arm 20 relative to connector body 12. The size of spring 46 can be adjusted to adjust the amount of force required to move a distal end 54 of latch arm 20 away from connector body 12.

Latch arm 20 further includes a tooth 56 at distal end 54 which is received over latch bolt 22 as shown to interconnect the connector bodies 12. Hence, to disconnect the connectors

10, tooth 56 must be moved out of alignment with connector body 12 so that it may pass over latch bolt 22. Alternatively, latch bolt 22 may be rotated so that tooth 56 may freely slide over bolt 22 as described in greater detail hereinafter. Referring to Fig. 5, construction of latch arm 20 will be described further. Latch arm 20 includes a cylindrical hole 58 which receives pivot pin 44 (see Fig. 4) so that latch arm 20 may pivot relative to connector body 12.

Figs. 6 and 7 illustrate construction of latch bolt 22. As previously described, latch bolt 22 includes a lever arm 42 which may be used to manually rotate latch bolt 22. Latch bolt 22 further includes a planar face 60 over which tooth 56 of latch arm 20 will slide. As best shown in Fig. 4, latch bolt 22 is received into a cylindrical slot 62 to allow latch bolt 22 to rotate about its central axis. The amount of rotation is controlled by a torsion spring (not shown) that is located under lever arm 42. The torsion spring tends to maintain latch bolt 22 in the position illustrated in Figs. 1 and 4.

Figs. 8-10 illustrate cooperation of latch arm 20 and latch bolt 22 to interlock the connectors. As illustrated in Fig. 8, as latch arm 20 comes into contact with latch bolt 22,

tooth 56 will begin to slide over face 60. Tooth 56 has an inclined surface to help assist in sliding tooth 56 over face 60. As shown in Fig. 9, as latch arm 20 is further advanced, the force of the torsion spring is overcome and allows latch bolt 22 to rotate in a clockwise direction until face 60 is generally parallel with slot 24 (see Fig. 1) . After tooth 56 has passed over face 60, the torsion spring causes latch bolt 22 to rotate counterclockwise to its normal position, thereby allowing tooth 56 to engage therewith and to securely mate the two connectors.

Once the connectors are completely joined, they may be disconnected by manually torquing on lever arm 42 (see Fig. 7) to place face 60 in the position illustrated in Fig. 9 so that the connectors may slide apart. Alternatively, the two connectors may be separated by axially pulling them apart. The amount of axial force required to separate the connectors is determined by the stiffness of spring 46. For most rail car connections, it will be desirable to have the connectors remain together until experiencing an axial force of approximately two hundred pounds per square inch. At this point, spring 46 will begin to compress to allow distal end 54 to move outward relative to connector body 12 and allow tooth 56 to pass over latch bolt 22.

Referring now to Fig. 11, construction of electrical contacts 32 and 34 will be described in greater detail.

Contacts 32 are constructed to mate with contacts 34 so that when the two connectors 10 are joined together the electrical contacts will also mate. In this way power or other electrical signals may be passed through conductors 30. Although the foregoing invention has been described in some detail by way of illustration and example, for purposed of clarity of understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims.