GB2534356A - Air brake and air line safety, connector - Google Patents

Abstract

A fluid line connector 1 has a weak breakage point (5, fig 1) that breaks rather than the line or hose to which it is attached. The connector can be cylindrical and contain 1 or 2 (fig 5) non-return valves 8. An interior flange of an opening 13 attaches to a groove 11A found on male fittings 7,11 of a heavy goods vehicle airline or brake line (6, fig 2). The openings may be rubber. The connector can break before the airline when the airline is taut in the event of jack-knifing, and then be replaced by a new connector. The connector can also be used for food or chemicals.

Description

AIR BRAKE AND AIR LINE SAFETY, REPLACEMENT CONNECTOR

Field of the Invention

The present invention relates to the maintenance of air lines and the ability to re-connect them after they have become damaged, including but not in particular vehicle or HGV air brake coils using a coupling connector method.

Background

The use of air lines in many areas of industry is common and include any area of application where air flow that is pressured or controlled is required to perform and inherent task. This include the use of air lines connecting the cab of a vehicle, moreover a lorry of heavy goods vehicle (HGV to the trailer for supply of air, which includes the air for the operation of the vehicles air brake system. An air brake or, more formally, a compressed air brake system, is a type of friction brake for vehicles in which compressed air pressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle.

Air brakes are used in large heavy vehicles, particularly those having multiple trailers which must be linked into the brake system, such as trucks, buses, trailers, and semi-trailers in addition to their use in railroad trains. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5,1872. Westinghouse made numerous alterations to improve his air pressured brake invention, which led to various forms of the automatic brake. In the early 20th century, after its advantages were proven in railway use, it was adopted by manufacturers of trucks and heavy road vehicles. Air brake systems are typically used on heavy trucks and buses.

The system consists of service brakes, parking brakes, a control pedal, and an air storage tank. For the parking brake, there is a disc or drum brake arrangement which is designed to be held in the 'applied' position by spring pressure. Air pressure must be produced to release these "spring brake" parking brakes. For the service brakes (the ones used while driving for slowing or stopping) to be applied, the brake pedal is pushed, routing the air under pressure (approx. 100-120 psi or 690-830 kPa) to the brake chamber, causing the brake to be engaged. Most types of truck air brakes are drum brakes, though there is an increasing trend towards the use of disc brakes in this application. The air compressor draws filtered air from the atmosphere and forces it into high-pressure reservoirs at around 120 psi (830 kPa).

Most heavy vehicles have a gauge within the drivers view, indicating the availability of air pressure for safe vehicle operation, often including warning tones or lights. Setting of the parking/emergency brake releases the pressurized air in the lines between the compressed air storage tank and the brakes, thus allowing the spring actuated parking brake to engage. A sudden loss of air pressure would result in full spring brake pressure immediately.

A compressed air brake system is divided into a supply system and a control system. The supply system compresses, stores and supplies high-pressure air to the control system as well as to additional air operated auxiliary truck systems (gearbox shift control, clutch pedal air assistance servo, etc.). The air compressor is driven by the engine either by crankshaft pulley via a belt or directly from the engine timing gears. It is lubricated and cooled by the engine lubrication and cooling systems.

Compressed air is first routed through a cooling coil and into an air dryer which removes moisture and oil impurities and also may include a pressure regulator, safety valve and smaller purge reservoir. As an alternative to the air dryer, the supply system can be equipped with an anti-freeze device and oil separator. The compressed air is then stored in a reservoir (also called a wet tank) from which it is then distributed via a four way protection valve into the front and rear brake circuit air reservoir, a parking brake reservoir and an auxiliary air supply distribution point. The system also includes various check, pressure limiting, drain and safety valves.

Air brake systems may include a wig wag device which deploys to warn the driver if the system air pressure drops too low. The control system is further divided into two service brake circuits: the parking brake circuit and the trailer brake circuit. This dual brake circuit is further split into front and rear wheel circuits which receive compressed air from their individual reservoirs for added safety in case of an air leak.

The service brakes are applied by means of a brake pedal air valve which regulates both circuits. The parking brake is the air operated spring brake type where its applied by spring force in the spring brake cylinder and released by compressed air via hand control valve. The trailer brake consists of a direct two line system: the supply line (marked red) and the separate control or service line (marked blue). The supply line receives air from the prime mover park brake air tank via a park brake relay valve and the control line is regulated via the trailer brake relay valve. The operating signals for the relay are provided by the prime mover brake pedal air valve, trailer service brake hand control (subject to a country's relevant heavy vehicle legislation) and the prime mover park brake hand control.

Air brakes are used as an alternative to hydraulic brakes which are used on lighter vehicles such as automobiles. Hydraulic brakes use a liquid (hydraulic fluid) to transfer pressure from the brake pedal to the brake shoe to stop the vehicle. Air brakes have several advantages for large multitrailer vehicles. The supply of air is unlimited, so the brake system can never run out of its operating fluid, as hydraulic brakes can. Minor leaks do not result in brake failures.

Air line couplings are easier to attach and detach than hydraulic lines; there is no danger of letting air into hydraulic fluid. So air brake circuits of trailers can be attached and removed easily by operators with little training. Air not only serves as a fluid for transmission of force, but also stores potential energy. So it can serve to control the force applied. Air brake systems include an air tank that stores sufficient energy to stop the vehicle if the compressor fails. Air brakes are effective even with considerable leakage, so an air brake system can be designed with sufficient "fail-safe" capacity to stop the vehicle safely even when leaking.

As air brakes must be operated differently from more common hydraulic systems, most countries require additional training and licensing in order to legally drive any vehicle using an air brake system. Driving a vehicle with air brakes requires basic knowledge of proper maintenance as well. A driver is required to inspect the air pressurization system prior to driving and make sure all tanks are in working order. In addition, the manner of applying brakes is usually different from regular hydraulic type systems. Pressure is applied slowly and air levels must be monitored at all times as a loss in air pressure will result in brake lockup aka "dynamiting". Unlike hydraulic brakes, air brakes must not be pumped repeatedly as the repetitive application and release of air will drain the system premature. During operation the air is supplied to the vehicle components via the coiled air tubes.

The air tubes provide a suitable way of transporting the required air at suitable pressure to attached areas of the heavy vehicle, including the trailer.

As is common with heavy goods vehicles they have occasions where they are subject to trauma, such as a 'jack knife' where the trailer is forced into a position where its rear moves too close to the frontal area of the vehicle or cab resulting in a 'V type of shape. If a vehicle towing a trailer skids, the trailer can push from behind until it spins round and faces backwards. This may be caused by equipment failure, improper braking, or adverse road conditions such as an icy road surface. In extreme circumstances, a driver may attempt to deliberately jackknife the vehicle in order to halt it following brake failure.

When an articulated vehicle jackknifes, the cab ends up facing in the opposite direction to the trailer. As such it is impossible for the cab (which contains the engine) to move and the vehicle becomes stuck. Since a jackknifed trailer is almost always facing sideways across the lanes of a road, and since it can no longer move, these sorts of accidents can cause major congestion on roads, even if there is relatively little damage to vehicles.

When a trailer skids to one side, this is known as a trailer swing or trailer slew. This could happen on a slippery road surface, often where there is a cant. This is not the same as "jackknifing" and is not as serious since the trailer moves back into line as the vehicle continues forwards. The driver must be aware, however, that the trailer could slide up against parked cars or a guard rail, or the wheels could slide into a ditch. This situation can occur especially when the trailer is empty or lightly loaded, and weather conditions cause violent gusts of crosswind. One system with limited success was a device that mechanically limited the angle which a trailer could swing.

Therefore, way to make the vehicles safer and methods of 'anti jackknifing' have been developed. A successful system was to fit the tractor with anti-lock brakes. Fitted originally to airplanes in the 1950s, anti-lock brakes have significantly reduced the number of heavy vehicle accidents.

Electronic brake force distribution varies the pressure to the rear brakes during heavy load or hard braking, enhancing driver control.

Tractors used to be fitted with a lever in the cab to operate the trailer brakes. The vehicle could be slowed down or stopped using the trailer brakes only. Theoretically this was a sure way to prevent jackknifing, but truck drivers will have noticed the recent disappearance of this lever from their cabs. The reason is that this lever was often the cause of jackknifing in a roundabout way. Frequent use of the trailer brakes alone caused them to overheat and fade while the tractor brakes remained fresh. In the event of an emergency stop, the driver would go straight for the foot brake and the truck would surely jackknife because the tractor brakes would lock while the trailer brakes would be ineffective due to previous overheating.

An alternative to having a trailer brake lever in the cab is to fit the trailer with an electromagnetic brake.

This action of jackknifing also has serious effect upon the air brake coils that connect between the cab and the trailer. During jackknifing incidents these coils split and the air brakes are locked, disabling the vehicle until a new complete air tube coil can be fitted.

Once damaged or split the coils are useless and must be replaced under current and known solutions. This is very time consuming and costly and it is noted that if this damage is apparent on vehicle air coils or lines, it may be possible that there are other types of air line found in other areas of usage that also tend to break or split under certain circumstances, as with the coils on a vehicle, there is also a certain point or area near where the air brake coils attach to the lorry cab area.

If this repeated area of breakage is found in other areas where air lines tubes are used, then this solution may be applied therein. This occurs depending on the drivers usage, but mainly when jack knifing into difficult spaces and the air lines are stretched and split at the weakest part. this is usually around the connector to the tractor unit since this is where the pulling is initiated in the manoeuvring.

Within logistics this happens possibly every several weeks or less depending on the kind of work undertaken. Around the world there are an estimated 12 million trucks on average according to available figures from research. This action of the air tube coils splitting initiates all the trailer brakes and if the air we're to release easily there would be damaging results. As an example, if travelling at regulated road speeds the brakes came to a sudden halt for no apparent reason other than a weak air line, then this would prove a dangerous system.

It is suggested and disclosed within this document that the section of the air tube or line which tends to repeatedly break is pre-installed with section of tubing that can break and then be removed and a new section inserted, without having to replace the whole coil.

This tube would attached to two male fitting members positioned at the end of the air coil and on the area of the vehicle cab rear, having female openings that locate and secure it in place using a press fitting.

Thus, if the vehicle jackknifes or other trauma is applied to the air coil of the vehicle and it breaks, the air is released under less haste and the resulting trauma reduced upon the vehicle and the driver and it will be the pre-installed section of tubing which actually breaks, instead of the coil itself and thus only the small connector has to be continually replaced.

Therefore, this replacement connector system is not designed to snap easily but slightly less easily and within the boundaries of existing laws which require service brakes to work around 100-125 psi.

Therefore, if the air line is pulled too tort, then the connector snaps at its weakest point allowing all the safety functions to occur on the trailers system as normal. However rather than replace a whole airline, the replacement connector can be fitted quickly and in a fraction of the time The connector can also be fitted with a non-return valve so that should the application be related to food products, chemicals or another systems or processes requiring that the product does not leak for either environmental, production, hygiene or process reasons then the return vales will hold the pressure, product etc. required for the process. Non return valves can be produced at both ends of these devices ensuring product contamination, food safety and environmental issues are to a minimum / nonexistence. The Figures enclosed show only one return value system but this can be if required shown at both ends as well as with no return valve in place.

It is suggested and disclosed within this document that the section of the air tube or line which tends to repeatedly break is pre-installed with section of tubing that can break and then be removed and a new section inserted, without having to replace the whole coil.

This tube would attached to two male fitting members positioned at the end of the air coil and on the area of the vehicle cab rear, having female openings that locate and secure it in place using a press fitting.

Thus, if the vehicle jackknifes or other trauma is applied to the air coil of the vehicle and it breaks, it will be the pre-installed section of tubing which actually breaks, instead of the coil itself and thus only the small connector has to be installed. This action can be repeated every time the connector break thus saving time and expense, plus keeping the working vehicle in action throughout.

Summary of the invention

According to the present invention there is provided a device that is of tubular form. The tube having a walled interior structure providing a hollowed interior that may accommodate other insertions but is on its own, able to provide a measured amount of strength in its composition. To each end of the tubed form are openings which provide a through and correspond to the diameter of the male parties onto which it is to be attached.

The subject herein is of a variant material. Possibly a flexible composite material such as a rubber to allow the openings to expand upon application over the male parts of the solution. The male parts referred to are the ends of the coiled air lines and the attachment point located to the rear of the cab of a heavy goods vehicle. The coiled air lines extend, on a heavy goods vehicle, from the trailer area in the known way toward the rear of the cab, drivers location. Normally the whole air coil or tube is stretched to meet fittings at the cab rear to connect air flow for usage including the air brakes of the vehicle.

The tube is a intervention in this normal application of the coil as it is attached primarily to the air outlet from the cab, instead of the coil directly, it then extends in a short length to couple with the end of the air tube coil from the trailer, as is shown in Figure 2.

Thus, a continued connection of the air flow from cab to trailer is provided, with the primary connection to the cab male fitting being led by the device.

The exterior of the subject device is, as mentioned tubed but may vary in external form and shape if desired, two larger collars are located to each end of the device which provide an area for the openings and for grip or purchase in use, which may also be assisted by having a textured or ribbed exterior, so when handled the person is more easily able to grip or hold the tube with reduced slippage.

The centre of the tubed form is designed to be more resilient upon it being flexed or bent to the point where it would normally snap or break. Thus as the connector device is broken, the breaking safety mechanisms action occurs more readily and in an improved time.

It may be possible to provide none-retuned valves to one or both ends of the connector device, as mentioned when certain rules and requirements are apparent, such as food and chemical industries where escape of air or other gases is not favourable. The heavy vehicle or air brake connector may not need these, as aforementioned.

Upon fitting, the openings to each end which results from the through of the hollow therein, are sized to be pressed over the slightly coned or straight fittings of the supplying members. These male end fitting members accommodate the openings over their diameter and secure them with a grove on their surface, corresponding with a flange or other protrusion and securing thus.

Once in place the connector device completes the air line and pressured air is able to flow through to the air brakes or other requirements. The interior hollow region of the connector device has a capacity and tubed diameter that is sufficient to ensure that the amount of air passing within and through its chamber is of a level and a constant that is exacting to that within the supply means, ensuring correct and even pressures.

Brief description of figures

Figures 1 show an example of the connector device for use with equipment that requires a none-return valve.

Figures 2 show an example of the connector device in location to the air tube coil as used on a heavy goods vehicle or similar.

Figures 3 show an example of the connector device as used with an air brake system, as found on but not exclusively heavy goods vehicles with trailers.

Figures 4 show a typical example of the connector device as a dimensional image.

Figures 5 show an example of the connector device with two none-return valves for added safety when in certain usage.

Detailed description of fiqures

A typical embodiment of the invention is illustrated in Figure 1. This shows the connector device body 1 which is an elongated cylindric form having a through hollow that results in openings at each end.

Connector collars 2 and 3 form more comprehensive areas to each end of the body 1 and provide openings 13 that engage over male fittings 7 which enable coupling of 1 and 7 and 11.

The body 1 is pressed onto the male fittings 1 and 7 which are suppliers of air flow from the vehicle trailer air hose 6 and with 11 and 4 providing the air from the driving area or cab therein, via male coupling openings 12 and 14.

The attachment of the body 1, via connecting collars 2 and 3 is assisted by a groove 11A found on one or more male couplings 7 and/or 11, corresponding with the interior flange of the connecting collar opening 13.

The breakage point 5 is more central to the body 1 and is a common area where the body 1 will break or snap upon trauma or the vehicle to which these are all attached being subject to a jack-knife action. This breakage in a heavy good vehicle would not require in most or all instances a none-retum valve 8 in a housing 10 and a supporting ring 9, as shown. Figure 1 shows an example with a none-return valve 8, more common with use in relation to food or chemicals, a heavy good vehicle option without 8 or 10 is shown in Figure 3.

The air brake coil supply 15 from the trailer, as shown in Figure 2 extends as a coiled length or tubing 6A, in the known way toward the heavy goods vehicle driver or cab area 17 to dock with the connecting device 1A. This is provided by press or push fittings, as shown, which vary in the known way and link to the hose connector 16 and the air to cab connector 3A mounted from the supply member 18. A connector device 1B for use with heavy goods vehicles and but not exclusively air brake system coils is shown in Figure 3 without internal none-return valves. This is due to the fact that they would not always be required when this type of connect device breaks, as the safety systems set within the vehicle breaking mechanisms must be allowed to engage in a suitable way.

The connector device 1C having cylindric or tubed form is shown dimensionally in Figure 4 with the connecting collars 2C to opposing ends, providing openings 13C which engage with the male fittings on the ends of the air lines and air suppliers, with an internal flange 19 which ensures secure connectivity by passing into a groove or opening to the surface of the male fittings, thus securing a true coupling to all parties.

Figure 5 shows the connector device with two none-return valves 8D which may be desired in certain terms or areas of usage to provide added security that no air can escape, to include use with food, chemical or volatile and toxic materials within industry.