CA2195608A1 - Vehicle safety monitoring system - Google Patents
Vehicle safety monitoring systemInfo
- Publication number
- CA2195608A1 CA2195608A1 CA 2195608 CA2195608A CA2195608A1 CA 2195608 A1 CA2195608 A1 CA 2195608A1 CA 2195608 CA2195608 CA 2195608 CA 2195608 A CA2195608 A CA 2195608A CA 2195608 A1 CA2195608 A1 CA 2195608A1
- Authority
- CA
- Canada
- Prior art keywords
- wheel
- vehicle
- wheels
- movement
- assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
- B60T17/18—Safety devices; Monitoring
- B60T17/22—Devices for monitoring or checking brake systems; Signal devices
- B60T17/221—Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
- F16D66/02—Apparatus for indicating wear
- F16D66/021—Apparatus for indicating wear using electrical detection or indication means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
- F16D66/02—Apparatus for indicating wear
- F16D66/021—Apparatus for indicating wear using electrical detection or indication means
- F16D66/022—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness
- F16D66/023—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness directly sensing the position of braking members
- F16D66/024—Sensors mounted on braking members adapted to contact the brake disc or drum, e.g. wire loops severed on contact
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
- F16D66/02—Apparatus for indicating wear
- F16D66/021—Apparatus for indicating wear using electrical detection or indication means
- F16D66/022—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness
- F16D66/025—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness sensing the position of parts of the brake system other than the braking members, e.g. limit switches mounted on master cylinders
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/14—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring distance or clearance between spaced objects or spaced apertures
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
- F16D2066/003—Position, angle or speed
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Transportation (AREA)
- Regulating Braking Force (AREA)
Abstract
A wheel and brake monitoring system for a truck. The system is capable of detecting looseness of any wheel assembly or excessive brake travel. Looseness of a wheel assembly is detected by sensing lateral movement of the assembly or rotational movement between two wheels of that assembly. Brake travel is monitored by sensing the travel of the brake actuator at each wheel.
Description
'_ 21 95608 BP #9565-001 /DL
BERESKIN & PARR C A N A D A
Title: VEHICLE SAFETY MONITORING SYSTEM
Inventor: CHARLES OLIVIER
Title: VEHICLE SAFETY MONITORING SYSTEM
FIELD OF THE INVENTION
This invention relates to a safety monitoring system for vehicles such as transport trucks and trailers.
BACKGROUND OF THE INVENTION
Recently, considerable media attention has been given to traffic accidents caused by a wheel or wheel assembly becoming detached from a transport truck while the truck is in motion. Once separated from the truck, a detached wheel or wheel assembly becomes an uncontrolled projectile that has considerable weight and momentum. A number of serious injuries and deaths have resulted from such incidents.
While there are requirements for periodic mechanical inspections of transport trucks, generally, monitoring of the mechanical condition and general roadworthiness of such vehicles relies on the diligence and thoroughness of the truck operator and/or driver. Given economic pressures to keep such vehicles in productive use, maintenance and repairs are sometimes neglected. Random unpredictable component failures can of course also be the cause of accidents.
An object of the present invention is to provide a safety monitoring ~yslem for vehicles such as transport trucks and trailers.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a safety monitoring ~yslem for the wheels of a vehicle in which each wheel rotates on a carrier that is rotationally supported on the vehicle itself. The system includes sensing means adapted to detect excessive axial movement of a wheel outwardly of the vehicle, and rotational movement of a wheel with respect to the associated wheel carrier, together with alarm means adapted to provide a warning in the event of either excessive axial movement of a wheel or rotation movement with respect to the associated wheel carrier.
The invention is based on the recognition that it is possible to detect defects that could result in a wheel or wheel assembly becoming 21 95~08 detached from the vehicle by monitoring either of these two eventualities.
Excessive axial movement of a wheel can occur, for example, in the event of catastrophic failure of a wheel bearing -- allowing the entire wheel assembly to come off the axle. Rotational movement of a wheel with respect to the associated wheel carrier will occur if the wheel studs that hold the wheel to the carrier shear.
In principle, the monitoring ~y~Lem of the invention can be applied to a single wheel carried by a hub, in which case the system detects rotational movement of the wheel with respect to the hub. In the case of a dual wheel vehicle having a pair of wheels mounted side-by-side coaxially on the same hub, detection can be effected by sensing relative rotational - movement between the two wheels or between one wheel and the hub.
Preferably, of course, sensing means is provided on each wheel of the vehicle, although sensing means could be used on only some wheels of the vehicle, for example, only on the dual wheels where the vehicle has both dual wheels and single wheels.
The alarm means may comprise a visual display panel to alert the driver to a possible malfunction. The display panel can be designed to identify which particular wheel assembly is defective.
In another aspect of the invention, the monitoring system may be applied to the brakes of the vehicle. This aspect of the invention may be used in combination with the wheel monitoring ~y~l~m discussed previously, or separately. In this aspect of the invention, the monitoring ~yslell~ is applied to a vehicle having at each wheel a brake actuator including an actuator element that is movable generally longitudinally at each actuation of the vehicles brakes. The system includes means associated with the actuator element of each brake actuator and responsive to said generally longitudinal movement of the element beyond a predetermined limit, together with alarm means adapted to provide a waming if movement beyond the limit occurs at any of the actuators.
In Ontario, the brakes of a transport truck are required to be set so that the actuator element at each wheel has a maximum travel of two inches. If travel beyond that amount is discovered during an inspection of the vehicle, heavy fines are levied. In a vehicle equipped with a monitoring ~yslelll according to the invention, the ~y~Le~"-may be adjusted to respond and provide a warning if the travel of the actuator element of any one wheel approaches that maximum. This will give the opportunity to adjust the brakes to avoid contravention of applicable regulations.
Different travel limits no doubt will apply in different jurisdictions and the sy~len prerelably is adjustable so that the driver or operator can maintain the brakes within whatever regulations apply or within safety limits determined by the individual driver or operator.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate a number of preferred embodiments of the invention by way of example, and in which:
Fig. 1 is a partial perspective view of a transport tractor unit, partly broken away to show a hub assembly of one wheel;
Fig. 2 is an exploded perspective view of a typical such assembly;
Fig. 3 is an elevational view of a sensor ring that may be used in the assembly of Fig. 2;
Fig. 4 is a simplified exploded view showing the sensing means of the invention in association with the sensor ring of Fig. 3;
Fig. 5 is a diagrammatic elevational view corresponding to Fig. 4, showing the two wheels assembled with the sensor ring and sensor;
Fig. 6 is an exploded perspective view showing an alternative wheel rim configuration;
Fig. 7 is a schematic illustration of a brake monitoring system in accordance with the invention;
Fig. 8 is a block diagram illustrating the overall monitoring ~y~lem; and, Fig. 9 is a simplified illustration of a driver display panel that may be used as part of the system showed in Fig. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to Fig. 1, a tractor unit is generally indicated at 20 and is shown without ancillary components such, for example, as a fifth wheel assembly. The cab is indicated at 22 and the chassis of the vehicle at 24. Four rear wheel assemblies of the tractor unit are shown and are individually denoted 26.
The frontmost wheel assembly at the left-hand side of the tractor unit in Fig. 1 is shown broken away at 28 to reveal the brake and hub assembly, generally denoted 30, on an axle 32 of the unit. A drum brake assembly is shown at 34 and an actuator for the brake at 36.
Typically, the brakes are air-operated.
It will be seen that each of the wheel assemblies 26 is a dual wheel assembly com~ising two wheels disposed coaxially side-by-side and carried by the same hub assembly. Fig. 2 shows a typical such wheel and hub assembly in exploded form and without the tires. The rims of the two wheels are indicated at 38 and 40 and are disposed outwardly of the hub assembly 30.
Hub assembly 30 includes a brake drum 42 and a wheel carrier in the form of a hub 44, which is rotationally supported on the axle 32 of the vehicle by a wheel bearing (not shown). A series of studs 46 extend through aligned holes in the hub 44, brake drum 42 and wheel rims 38 and 40 to clamp the whole assembly to the axle. Nuts for the studs are shown at 48, outwardly of wheel rim 38.
Typically, each of the wheel rims 38 and 40 includes openings such as those shown at 50. When the two wheel rims are clamped together by the studs 46 and nuts 48, the openings in the respective rims are aligned with one another.
The housing of axle 32 (Fig. 1) is diagrammatically indicated in Fig. 2 at 52 and is fitted with a sensor 54 positioned to direct a sensing beam 56 through the aligned openings 50 in the wheel rims 38 and 40. As 21 95~0~
-the wheel assembly rotates, beam 56 will be repeatedly interrupted by the solid portions of the two wheel rims between the openings 50, providing a pulsed signal. In the event that excessive relative rotation takes place between the two wheel rims 38 and 40, the signal from sensor 54 will change, or possibly be cut off if the two wheels turn with respect to one another to an extent sufficient that the openings 50 are no longer aligned.
The systelll will then provide an alarm to the effect that the wheel assembly in question has developed a defect.
Sensor 54 is also sensitive to the distance of the inner wheel rim 40 from the switch. For example, the sensor may be designed to in effect "measure" that distance during the time when beam 56 is interrupted by the solid portions of the rim between the openings 50. The sensor can then respond and give an alarm signal in the event that that distance exceeds a defined maximum value, indicating excessive axial outward movement of the wheel assembly.
With certain types of wheel rims, it is conventional to provide an annular ring between the two rims, primarily to protect the rims against mechanical damage due to vibration and slight relative movement when the vehicle is in motion. A typical such ring is indicated at 58 in Fig. 2 and is shown in elevation in Fig. 3. The ring has openings 60 to receive the wheel studs 46. According to another aspect of the invention, the ring 58 may be used as a re~r~llce that is sensed by sensors of the monitoring ~yslem to detect abnormalities. It may be necessary to radially enlarge the ring as compared with conventional protective rings.
Fig. 4 shows such an arrangement, in simplified exploded form. Two wheels of a typical wheel assembly 26 are shown (with tires) in exploded positions at 62 and 64 with a sensor ring 58 in between. A sensor such as a proximity switch assembly 66 is carried at the distal end of an arm 68, the opposite end of which is secured to the axle housing 52 of the vehicle. Arm 68 should be relatively rigid but may be adjustable or capable of being bent so that its shape can be changed to fit different vehicles and bring the proximity switch assembly 66 into appropriate relationship with -ring 58.
Fig. 5 is a diagrammatic illustration showing the two wheel rims 38 and 40 (of the wheels 62 and 64) in their assembled condition, with the sensor ring 58 between the two rims. The proximity switch assembly 5 66 is positioned adjacent the outer edge face of ring 58 as it rotates.
Assembly 66 is designed to be responsive to the axial position of ring 58 with respect to the longitudinal axis A-A of the wheel assembly, and to the relative rotational positions of the two rims 38 and 40. For example, the assembly may include a proximity switch, a signal from which is 10 represented by the arrow denoted 70 in Fig. 5, and which will respond to any axial movement of ring 58 beyond a prescribed limit. A response to such movement beyond the limit will of course indicate excessive axial movement of the wheel assembly and provide an alarm signal, indicating possible hub bearing failure.
Assembly 66 will also include sensors that are responsive to the relative rotational positions of the two rims 38 and 40, as indicated by the arrows denoted 72 and 74. For example, these sensors may also be proximity switches that respond to the presence or the absence of the openings 50 in the wheel rims (see Fig. 2). These sensors will accordingly 20 provide timed pulses that will co-incide as long as there is no relative rotational movement between the two rims. When the system detects that the pulses represented by the arrows 72 and 74 are out of phase, the ~y~e-ll will recognize that excessive rotational movement has taken place between the two rims, for example indicating that the wheel studs have 25 sheared, and provide an alarm signal.
Fig. 6 shows an alternative style of wheel rim, the two rims corresponding to the rims 38 and 40 of the previous views being denoted 38' and 40'. This style of wheel rim is designed so that each rim has marginal flanges at each side, as indicated at F. When assembled together, 30 the marginal flange F at the outer side of the rim of the inner wheel (rim 40') confronts the corresponding flange at the inner side of the rim of the outer wheel (rim 38'). A spacer 76 of short cylindrical form is fitted between the two rims and is in effect clamped by the wheel studs and nuts.
Where this style of wheel rim is used, the spacer 76 can be used to provide the reference for the sensor assembly such as assembly 66 in Figs. 4 and 5.
The proximity switch represented by the arrow 70 in Fig. 5 can be used to 5 "read" the spacer and respond to any deviation from its "datum" axial location when the wheel assembly is fully tightened onto the hub (44 --Fig. 2). If necess~ry, openings or markings can be provided on the spacer to be "read" by the sensor.
The previous description of course relates to aspects of the 10 monitoring system of the invention that are designed to detect and respond to defects in a wheel assembly. Fig. 7 illustrates the aspect of the invention that relates to monitoring brake actuator travel. A typical brake actuator is illustrated in simplified form and denoted 78. As mentioned previously, each wheel of the vehicle will be provided with one of these 15 actuators. The actuators are air-operated and are essentially conventional.
Reference numeral 80 denotes a housing for an air-responsive piston of the actuator. A brake actuator rod 82 projects from one end of the housing and has a clevis 84 at its distal end by which the actuator is coupled to the actual brake mechanism (not shown). When the driver applies the brakes, 20 air is supplied to housing 80 to move rod 82 longitudinally with respect to housing 80 and apply the brakes.
According to this aspect of the invention, a sensor is associated with the actuator rod 82 and is arranged to be responsive to longitudinal movement of rod 82 at a predetermined threshold limit (e.g.
25 two inches). Fig. 7 shows two alternative arrangements. In one arrangement, the housing 80 is provided with an opening 86 (not present in a conventional brake actuator) and a sensor 88 is fitted into the housing so as to monitor longitudinal movement of rod 82 within the housing 80.
In an alternative arrangement, a sensor denoted 90 may be mounted on a 30 supporting bracket 92 so as to monitor movement of the rod externally of housing 80.
For example, the sensors may be proximity switches or other -sensors responsive to longitudinal displacement of a rod. Sensors that respond to markings or fittings on the rod (not shown) can be used.
Preferably, provision is made for adjustments so that the sensor can respond to different extents of actuator rod travel, as determined by applicable regulations or other safety criteria. If adjustability is required, it may be desirable to use an external sensor such as sensor 90. Adjustability may be provided by allowing for adjustment of the sensor position or adjustment of fittings on the actuator rod.
In a simple alternative example, one or more limit switches may be used, for example, a stationary limit switch co-operating with adjustable stops on rod 82.
- As mentioned previously, the brake monitoring aspect of the invention may be used in combination with or separately from the wheel monitoring aspect described previously. Conversely, the wheel monitoring aspect may be used without monitoring the brakes.
Preferably, however, the system integrates both functions.
Fig. 8 is a diagrammatic illustration of such an integrated system while Fig.
9 shows a corresponding display that may be provided within the driver's cab of the vehicle.
The box indicated at 94 in Fig. 8 represents a plan view of the tractor unit 20 of Fig. 1. The rear wheel assemblies 26 are shown as are two front wheel assemblies 96 (which may be single wheels). The display panel shown in Fig. 9 is represented at 98 and an electronic signal processor at 100. The various lines denoted 102 represent signals that are fed to the processor from the wheel assembly sensors and from the brake actuators described previously. Processor 100 may also receive signals representing vehicle speed if necessAry. An output signal path to panel 98 is indicated at 104. The display panel shown in Fig. 9 includes appropriately designated indicator lights for each wheel and for each of the brakes of the tractor (in the upper portion of the panel denoted 98a). The lower portion 98b of the panel includes corresponding indicator lights for a three axle trailer (not shown).
21 ~56v~
g It should of course be appreciated that the preceding description relates to particular preferred embodiments of the invention only and that many modifications are possible within the broad scope of the invention. While examples of sensor configurations and types have 5 been given, it should be noted in particular that applicant does not intend to be limited to any particular one of these examples and that different types of sensors and configurations may be used within the broad scope of the invention.
BERESKIN & PARR C A N A D A
Title: VEHICLE SAFETY MONITORING SYSTEM
Inventor: CHARLES OLIVIER
Title: VEHICLE SAFETY MONITORING SYSTEM
FIELD OF THE INVENTION
This invention relates to a safety monitoring system for vehicles such as transport trucks and trailers.
BACKGROUND OF THE INVENTION
Recently, considerable media attention has been given to traffic accidents caused by a wheel or wheel assembly becoming detached from a transport truck while the truck is in motion. Once separated from the truck, a detached wheel or wheel assembly becomes an uncontrolled projectile that has considerable weight and momentum. A number of serious injuries and deaths have resulted from such incidents.
While there are requirements for periodic mechanical inspections of transport trucks, generally, monitoring of the mechanical condition and general roadworthiness of such vehicles relies on the diligence and thoroughness of the truck operator and/or driver. Given economic pressures to keep such vehicles in productive use, maintenance and repairs are sometimes neglected. Random unpredictable component failures can of course also be the cause of accidents.
An object of the present invention is to provide a safety monitoring ~yslem for vehicles such as transport trucks and trailers.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a safety monitoring ~yslem for the wheels of a vehicle in which each wheel rotates on a carrier that is rotationally supported on the vehicle itself. The system includes sensing means adapted to detect excessive axial movement of a wheel outwardly of the vehicle, and rotational movement of a wheel with respect to the associated wheel carrier, together with alarm means adapted to provide a warning in the event of either excessive axial movement of a wheel or rotation movement with respect to the associated wheel carrier.
The invention is based on the recognition that it is possible to detect defects that could result in a wheel or wheel assembly becoming 21 95~08 detached from the vehicle by monitoring either of these two eventualities.
Excessive axial movement of a wheel can occur, for example, in the event of catastrophic failure of a wheel bearing -- allowing the entire wheel assembly to come off the axle. Rotational movement of a wheel with respect to the associated wheel carrier will occur if the wheel studs that hold the wheel to the carrier shear.
In principle, the monitoring ~y~Lem of the invention can be applied to a single wheel carried by a hub, in which case the system detects rotational movement of the wheel with respect to the hub. In the case of a dual wheel vehicle having a pair of wheels mounted side-by-side coaxially on the same hub, detection can be effected by sensing relative rotational - movement between the two wheels or between one wheel and the hub.
Preferably, of course, sensing means is provided on each wheel of the vehicle, although sensing means could be used on only some wheels of the vehicle, for example, only on the dual wheels where the vehicle has both dual wheels and single wheels.
The alarm means may comprise a visual display panel to alert the driver to a possible malfunction. The display panel can be designed to identify which particular wheel assembly is defective.
In another aspect of the invention, the monitoring system may be applied to the brakes of the vehicle. This aspect of the invention may be used in combination with the wheel monitoring ~y~l~m discussed previously, or separately. In this aspect of the invention, the monitoring ~yslell~ is applied to a vehicle having at each wheel a brake actuator including an actuator element that is movable generally longitudinally at each actuation of the vehicles brakes. The system includes means associated with the actuator element of each brake actuator and responsive to said generally longitudinal movement of the element beyond a predetermined limit, together with alarm means adapted to provide a waming if movement beyond the limit occurs at any of the actuators.
In Ontario, the brakes of a transport truck are required to be set so that the actuator element at each wheel has a maximum travel of two inches. If travel beyond that amount is discovered during an inspection of the vehicle, heavy fines are levied. In a vehicle equipped with a monitoring ~yslelll according to the invention, the ~y~Le~"-may be adjusted to respond and provide a warning if the travel of the actuator element of any one wheel approaches that maximum. This will give the opportunity to adjust the brakes to avoid contravention of applicable regulations.
Different travel limits no doubt will apply in different jurisdictions and the sy~len prerelably is adjustable so that the driver or operator can maintain the brakes within whatever regulations apply or within safety limits determined by the individual driver or operator.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate a number of preferred embodiments of the invention by way of example, and in which:
Fig. 1 is a partial perspective view of a transport tractor unit, partly broken away to show a hub assembly of one wheel;
Fig. 2 is an exploded perspective view of a typical such assembly;
Fig. 3 is an elevational view of a sensor ring that may be used in the assembly of Fig. 2;
Fig. 4 is a simplified exploded view showing the sensing means of the invention in association with the sensor ring of Fig. 3;
Fig. 5 is a diagrammatic elevational view corresponding to Fig. 4, showing the two wheels assembled with the sensor ring and sensor;
Fig. 6 is an exploded perspective view showing an alternative wheel rim configuration;
Fig. 7 is a schematic illustration of a brake monitoring system in accordance with the invention;
Fig. 8 is a block diagram illustrating the overall monitoring ~y~lem; and, Fig. 9 is a simplified illustration of a driver display panel that may be used as part of the system showed in Fig. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to Fig. 1, a tractor unit is generally indicated at 20 and is shown without ancillary components such, for example, as a fifth wheel assembly. The cab is indicated at 22 and the chassis of the vehicle at 24. Four rear wheel assemblies of the tractor unit are shown and are individually denoted 26.
The frontmost wheel assembly at the left-hand side of the tractor unit in Fig. 1 is shown broken away at 28 to reveal the brake and hub assembly, generally denoted 30, on an axle 32 of the unit. A drum brake assembly is shown at 34 and an actuator for the brake at 36.
Typically, the brakes are air-operated.
It will be seen that each of the wheel assemblies 26 is a dual wheel assembly com~ising two wheels disposed coaxially side-by-side and carried by the same hub assembly. Fig. 2 shows a typical such wheel and hub assembly in exploded form and without the tires. The rims of the two wheels are indicated at 38 and 40 and are disposed outwardly of the hub assembly 30.
Hub assembly 30 includes a brake drum 42 and a wheel carrier in the form of a hub 44, which is rotationally supported on the axle 32 of the vehicle by a wheel bearing (not shown). A series of studs 46 extend through aligned holes in the hub 44, brake drum 42 and wheel rims 38 and 40 to clamp the whole assembly to the axle. Nuts for the studs are shown at 48, outwardly of wheel rim 38.
Typically, each of the wheel rims 38 and 40 includes openings such as those shown at 50. When the two wheel rims are clamped together by the studs 46 and nuts 48, the openings in the respective rims are aligned with one another.
The housing of axle 32 (Fig. 1) is diagrammatically indicated in Fig. 2 at 52 and is fitted with a sensor 54 positioned to direct a sensing beam 56 through the aligned openings 50 in the wheel rims 38 and 40. As 21 95~0~
-the wheel assembly rotates, beam 56 will be repeatedly interrupted by the solid portions of the two wheel rims between the openings 50, providing a pulsed signal. In the event that excessive relative rotation takes place between the two wheel rims 38 and 40, the signal from sensor 54 will change, or possibly be cut off if the two wheels turn with respect to one another to an extent sufficient that the openings 50 are no longer aligned.
The systelll will then provide an alarm to the effect that the wheel assembly in question has developed a defect.
Sensor 54 is also sensitive to the distance of the inner wheel rim 40 from the switch. For example, the sensor may be designed to in effect "measure" that distance during the time when beam 56 is interrupted by the solid portions of the rim between the openings 50. The sensor can then respond and give an alarm signal in the event that that distance exceeds a defined maximum value, indicating excessive axial outward movement of the wheel assembly.
With certain types of wheel rims, it is conventional to provide an annular ring between the two rims, primarily to protect the rims against mechanical damage due to vibration and slight relative movement when the vehicle is in motion. A typical such ring is indicated at 58 in Fig. 2 and is shown in elevation in Fig. 3. The ring has openings 60 to receive the wheel studs 46. According to another aspect of the invention, the ring 58 may be used as a re~r~llce that is sensed by sensors of the monitoring ~yslem to detect abnormalities. It may be necessary to radially enlarge the ring as compared with conventional protective rings.
Fig. 4 shows such an arrangement, in simplified exploded form. Two wheels of a typical wheel assembly 26 are shown (with tires) in exploded positions at 62 and 64 with a sensor ring 58 in between. A sensor such as a proximity switch assembly 66 is carried at the distal end of an arm 68, the opposite end of which is secured to the axle housing 52 of the vehicle. Arm 68 should be relatively rigid but may be adjustable or capable of being bent so that its shape can be changed to fit different vehicles and bring the proximity switch assembly 66 into appropriate relationship with -ring 58.
Fig. 5 is a diagrammatic illustration showing the two wheel rims 38 and 40 (of the wheels 62 and 64) in their assembled condition, with the sensor ring 58 between the two rims. The proximity switch assembly 5 66 is positioned adjacent the outer edge face of ring 58 as it rotates.
Assembly 66 is designed to be responsive to the axial position of ring 58 with respect to the longitudinal axis A-A of the wheel assembly, and to the relative rotational positions of the two rims 38 and 40. For example, the assembly may include a proximity switch, a signal from which is 10 represented by the arrow denoted 70 in Fig. 5, and which will respond to any axial movement of ring 58 beyond a prescribed limit. A response to such movement beyond the limit will of course indicate excessive axial movement of the wheel assembly and provide an alarm signal, indicating possible hub bearing failure.
Assembly 66 will also include sensors that are responsive to the relative rotational positions of the two rims 38 and 40, as indicated by the arrows denoted 72 and 74. For example, these sensors may also be proximity switches that respond to the presence or the absence of the openings 50 in the wheel rims (see Fig. 2). These sensors will accordingly 20 provide timed pulses that will co-incide as long as there is no relative rotational movement between the two rims. When the system detects that the pulses represented by the arrows 72 and 74 are out of phase, the ~y~e-ll will recognize that excessive rotational movement has taken place between the two rims, for example indicating that the wheel studs have 25 sheared, and provide an alarm signal.
Fig. 6 shows an alternative style of wheel rim, the two rims corresponding to the rims 38 and 40 of the previous views being denoted 38' and 40'. This style of wheel rim is designed so that each rim has marginal flanges at each side, as indicated at F. When assembled together, 30 the marginal flange F at the outer side of the rim of the inner wheel (rim 40') confronts the corresponding flange at the inner side of the rim of the outer wheel (rim 38'). A spacer 76 of short cylindrical form is fitted between the two rims and is in effect clamped by the wheel studs and nuts.
Where this style of wheel rim is used, the spacer 76 can be used to provide the reference for the sensor assembly such as assembly 66 in Figs. 4 and 5.
The proximity switch represented by the arrow 70 in Fig. 5 can be used to 5 "read" the spacer and respond to any deviation from its "datum" axial location when the wheel assembly is fully tightened onto the hub (44 --Fig. 2). If necess~ry, openings or markings can be provided on the spacer to be "read" by the sensor.
The previous description of course relates to aspects of the 10 monitoring system of the invention that are designed to detect and respond to defects in a wheel assembly. Fig. 7 illustrates the aspect of the invention that relates to monitoring brake actuator travel. A typical brake actuator is illustrated in simplified form and denoted 78. As mentioned previously, each wheel of the vehicle will be provided with one of these 15 actuators. The actuators are air-operated and are essentially conventional.
Reference numeral 80 denotes a housing for an air-responsive piston of the actuator. A brake actuator rod 82 projects from one end of the housing and has a clevis 84 at its distal end by which the actuator is coupled to the actual brake mechanism (not shown). When the driver applies the brakes, 20 air is supplied to housing 80 to move rod 82 longitudinally with respect to housing 80 and apply the brakes.
According to this aspect of the invention, a sensor is associated with the actuator rod 82 and is arranged to be responsive to longitudinal movement of rod 82 at a predetermined threshold limit (e.g.
25 two inches). Fig. 7 shows two alternative arrangements. In one arrangement, the housing 80 is provided with an opening 86 (not present in a conventional brake actuator) and a sensor 88 is fitted into the housing so as to monitor longitudinal movement of rod 82 within the housing 80.
In an alternative arrangement, a sensor denoted 90 may be mounted on a 30 supporting bracket 92 so as to monitor movement of the rod externally of housing 80.
For example, the sensors may be proximity switches or other -sensors responsive to longitudinal displacement of a rod. Sensors that respond to markings or fittings on the rod (not shown) can be used.
Preferably, provision is made for adjustments so that the sensor can respond to different extents of actuator rod travel, as determined by applicable regulations or other safety criteria. If adjustability is required, it may be desirable to use an external sensor such as sensor 90. Adjustability may be provided by allowing for adjustment of the sensor position or adjustment of fittings on the actuator rod.
In a simple alternative example, one or more limit switches may be used, for example, a stationary limit switch co-operating with adjustable stops on rod 82.
- As mentioned previously, the brake monitoring aspect of the invention may be used in combination with or separately from the wheel monitoring aspect described previously. Conversely, the wheel monitoring aspect may be used without monitoring the brakes.
Preferably, however, the system integrates both functions.
Fig. 8 is a diagrammatic illustration of such an integrated system while Fig.
9 shows a corresponding display that may be provided within the driver's cab of the vehicle.
The box indicated at 94 in Fig. 8 represents a plan view of the tractor unit 20 of Fig. 1. The rear wheel assemblies 26 are shown as are two front wheel assemblies 96 (which may be single wheels). The display panel shown in Fig. 9 is represented at 98 and an electronic signal processor at 100. The various lines denoted 102 represent signals that are fed to the processor from the wheel assembly sensors and from the brake actuators described previously. Processor 100 may also receive signals representing vehicle speed if necessAry. An output signal path to panel 98 is indicated at 104. The display panel shown in Fig. 9 includes appropriately designated indicator lights for each wheel and for each of the brakes of the tractor (in the upper portion of the panel denoted 98a). The lower portion 98b of the panel includes corresponding indicator lights for a three axle trailer (not shown).
21 ~56v~
g It should of course be appreciated that the preceding description relates to particular preferred embodiments of the invention only and that many modifications are possible within the broad scope of the invention. While examples of sensor configurations and types have 5 been given, it should be noted in particular that applicant does not intend to be limited to any particular one of these examples and that different types of sensors and configurations may be used within the broad scope of the invention.
Claims (7)
1. A safety monitoring system for a vehicle having wheels, each of which rotates on a carrier that is rotationally supported on the vehicle, the system comprising:
sensing means adapted to detect excessive axial movement of a wheel outwardly of the vehicle and rotational movement of the wheel with respect to the associated wheel carrier, and alarm means adapted to provide a warning in response to either of excessive axial movement of a wheel or rotational movement of the wheel with respect to the associated wheel carrier.
sensing means adapted to detect excessive axial movement of a wheel outwardly of the vehicle and rotational movement of the wheel with respect to the associated wheel carrier, and alarm means adapted to provide a warning in response to either of excessive axial movement of a wheel or rotational movement of the wheel with respect to the associated wheel carrier.
2. A system as claimed in claim 1, wherein the vehicle includes at least one dual wheel assembly which includes a pair of wheels disposed coaxially side-by-side, and wherein said sensing means is adapted to detect said rotational movement of the wheel with respect to the associated wheel carrier by responding to relative rotational movement between the two wheels.
3. A system as claimed in claim 2, wherein said sensing means is carried by a housing of an axle on which said wheel assembly is rotationally supported, and wherein said sensing means is adapted to project a sensing beam through openings in rims of said dual wheels which are aligned when the wheels are correctly assembled on the vehicle and which is adapted to respond to misalignment of said openings or outward axial movement of the wheel assembly.
4. A system as claimed in claim 2, further comprising a sensor ring mounted between said wheels, and wherein said sensing means comprises a sensor assembly positioned adjacent an outer edge of said ring and adapted to respond to outward axial movement of said ring from a datum location and relative rotational movement between said wheels on opposite sides of said ring.
5. A system as claimed in claim 1, wherein said alarm means comprises a display panel adapted to provide a visual indication to a driver of the vehicle of a defect detected by said sensing means.
6. A system as claimed in claim 1, wherein said vehicle has, at each wheel, a brake actuator including an actuator element that is movable generally longitudinally at each actuation of the vehicles brakes, wherein the system further includes means associated with the actuator element at each said brake actuator and responsive to said generally longitudinal movement of the element beyond a predetermined limit, and wherein said alarm means is adapted to provide a warning if movement beyond said limit occurs at any of said actuators.
7. A safety monitoring system for a wheeled vehicle having, at each wheel, a brake actuator including an actuator element that is movable generally longitudinally at each actuation of the vehicles brakes, the system comprising means associated with the actuator element at each said brake actuator and responsive to said generally longitudinal movement of the element beyond a predetermined limit, and alarm means adapted to provide a warning if movement beyond said limit occurs at any of said actuators.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2195608 CA2195608A1 (en) | 1997-01-21 | 1997-01-21 | Vehicle safety monitoring system |
| CA 2216494 CA2216494A1 (en) | 1997-01-21 | 1997-10-01 | Vehicle safety monitoring system |
| PCT/CA1998/000013 WO1998031983A1 (en) | 1997-01-21 | 1998-01-09 | Vehicle safety monitoring system |
| AU55460/98A AU5546098A (en) | 1997-01-21 | 1998-01-09 | Vehicle safety monitoring system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2195608 CA2195608A1 (en) | 1997-01-21 | 1997-01-21 | Vehicle safety monitoring system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2195608A1 true CA2195608A1 (en) | 1998-07-21 |
Family
ID=4159711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2195608 Abandoned CA2195608A1 (en) | 1997-01-21 | 1997-01-21 | Vehicle safety monitoring system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2195608A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6341670B1 (en) | 1999-02-19 | 2002-01-29 | Rideau Bulk Ltd. | Brake wear managing system |
| WO2016120019A1 (en) * | 2015-01-27 | 2016-08-04 | Nira Dynamics Ab | Loose wheel detection |
-
1997
- 1997-01-21 CA CA 2195608 patent/CA2195608A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6341670B1 (en) | 1999-02-19 | 2002-01-29 | Rideau Bulk Ltd. | Brake wear managing system |
| WO2016120019A1 (en) * | 2015-01-27 | 2016-08-04 | Nira Dynamics Ab | Loose wheel detection |
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| Date | Code | Title | Description |
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| FZDE | Dead |