CA1179039A - Tire pressure communication devices - Google Patents
Tire pressure communication devicesInfo
- Publication number
- CA1179039A CA1179039A CA000440135A CA440135A CA1179039A CA 1179039 A CA1179039 A CA 1179039A CA 000440135 A CA000440135 A CA 000440135A CA 440135 A CA440135 A CA 440135A CA 1179039 A CA1179039 A CA 1179039A
- Authority
- CA
- Canada
- Prior art keywords
- tire
- tire pressure
- pressure
- races
- core
- 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.)
- Expired
Links
Abstract
TIRE PRESSURE COMMUNICATION DEVICES
ABSTRACT OF THE DISCLOSURE
Disclosed are devices for transmitting signals from a rotatable tire to a stationary recei-ver which correspond to the internal pressure of the tire. In one embodiment, a Bourdon tube communicates with internal tire pressure to regulate the magnetic gap of an electromagnetic induction configuration.
Changes in the magnetic gap result in corresponding changes in an output signal strength. In another embodiment of the invention, a bellows is provided in communication with tire pressure for regulating the position of the core of an LVDT. The core position and, accordingly, the output of the LVDT corresponds to tire pressure. In yet another embodiment, strain gauges or other appropriate electrical signal genera tors are connected to the tire and interconnected with a rotating race. A plurality of ball bearings are maintained in a preloaded condition between the rotating race and a stationary race, the latter race communicating signals to a tire pressure meter or the like.
ABSTRACT OF THE DISCLOSURE
Disclosed are devices for transmitting signals from a rotatable tire to a stationary recei-ver which correspond to the internal pressure of the tire. In one embodiment, a Bourdon tube communicates with internal tire pressure to regulate the magnetic gap of an electromagnetic induction configuration.
Changes in the magnetic gap result in corresponding changes in an output signal strength. In another embodiment of the invention, a bellows is provided in communication with tire pressure for regulating the position of the core of an LVDT. The core position and, accordingly, the output of the LVDT corresponds to tire pressure. In yet another embodiment, strain gauges or other appropriate electrical signal genera tors are connected to the tire and interconnected with a rotating race. A plurality of ball bearings are maintained in a preloaded condition between the rotating race and a stationary race, the latter race communicating signals to a tire pressure meter or the like.
Description
I 1~9V3~
1.
BAC~G~UND OF THE INVENTION
The instant invenkion resides in the ark of monitoring devices and is more particularly related to such devices for aircrat. It is extremely impor-tant that aircraft tire pressure be known to the pilot to reduce the possibility of blowouts. It is well known that the likelihood of a blowout substan-tially increases with tire pressure changes above or below a particular desired level, and that such blow-outs not only result in a loss of the tire itself, but seriously increase the likelihood of further property damage ~r human injury.
Hexetofore in the art, applicant has not been made aware of any tire pressure monitoring sys-tems which will allow a continual monitoring of the tire pressure during both static and dynamic condi-tions. Brushes have ~een used in the past to act as commutatoxs for transferring an electrical signal from a rotating to a stationary member. However, "brush dancing" is experienced when used in the environment of an aircraft wheel and noise or spuri-ous signals are generated which substantially reduce the integrity of the sensing system. Further, brush-es are subject to contamination in the wheel environ-ment and are generally characterized by an undesir-a~ly high resistance path.
The prior art has also taught certain types of interconnections between rotating and stationary members for transmitting tire pressure signals util-izing an induction technique. However, such systems have generally required close tolerances between the static and dynamic coils, which tolerances must not chanqe with movement of the wheel. Accord~ngly, concentricity problems have made such systems unsuit-able for the aircraft industry.
gO3~
1.
BAC~G~UND OF THE INVENTION
The instant invenkion resides in the ark of monitoring devices and is more particularly related to such devices for aircrat. It is extremely impor-tant that aircraft tire pressure be known to the pilot to reduce the possibility of blowouts. It is well known that the likelihood of a blowout substan-tially increases with tire pressure changes above or below a particular desired level, and that such blow-outs not only result in a loss of the tire itself, but seriously increase the likelihood of further property damage ~r human injury.
Hexetofore in the art, applicant has not been made aware of any tire pressure monitoring sys-tems which will allow a continual monitoring of the tire pressure during both static and dynamic condi-tions. Brushes have ~een used in the past to act as commutatoxs for transferring an electrical signal from a rotating to a stationary member. However, "brush dancing" is experienced when used in the environment of an aircraft wheel and noise or spuri-ous signals are generated which substantially reduce the integrity of the sensing system. Further, brush-es are subject to contamination in the wheel environ-ment and are generally characterized by an undesir-a~ly high resistance path.
The prior art has also taught certain types of interconnections between rotating and stationary members for transmitting tire pressure signals util-izing an induction technique. However, such systems have generally required close tolerances between the static and dynamic coils, which tolerances must not chanqe with movement of the wheel. Accord~ngly, concentricity problems have made such systems unsuit-able for the aircraft industry.
gO3~
2, Other approaches to sensing and tran~mit-ting electrical signals indicative of tire pressure have utilized magnets ~aintained within the wheel, operating upon a magnetic field principle. However, problems have been experienced with the carrying of magnets within the wheel due to size and weight requirements. Such systems have generally not been accepted. Similarly rejected as being insufficient have ~een the tire pressure indicators utilizing r 10 apparatus producing an audi~le signal. However, such systems have been of a nature that a signal is emit ted only during the period that the tire is actually goinq flat or losing pressure. If the operator is not near the tire or vehicle during the period that pressure is being lost, the signal will not be dis-cerned by anyone and the usefulness of such system will be totally lost.
It has there~ore ~ecome desirable to pro-vide in the art, a tire pressure communication device which provides substantially noise-free output sigW
nals while being of sufficiently simplistic nature (~ that it is capable of operating in the severe envir-onment of an aircraft wheel without reduction of system integrity.
ASl~:CTS OF THE IN~IENTION
In light of the foregoing, in accordance with one aspect of the invention, there ;s provided a tire pressure communication device which, without the presence of noise and spurious signals, communicate~
a signal indicative of tire pressure from a rotatable tire to a stationary portion of the aircraft.
In accordance with another aæpect of the invention, there is provided a tire pressure communi-cation device wherein no brushes are necessary for 1 17~()39
It has there~ore ~ecome desirable to pro-vide in the art, a tire pressure communication device which provides substantially noise-free output sigW
nals while being of sufficiently simplistic nature (~ that it is capable of operating in the severe envir-onment of an aircraft wheel without reduction of system integrity.
ASl~:CTS OF THE IN~IENTION
In light of the foregoing, in accordance with one aspect of the invention, there ;s provided a tire pressure communication device which, without the presence of noise and spurious signals, communicate~
a signal indicative of tire pressure from a rotatable tire to a stationary portion of the aircraft.
In accordance with another aæpect of the invention, there is provided a tire pressure communi-cation device wherein no brushes are necessary for 1 17~()39
3.
electrical communication from a rotating to a stationary structure.
In accordance with still another aspect of the invention, there is provided a tire pressure communication device wherein tolerance and concentricity problems inci-dent to the prior art are overcome and in which the prior art problems of contamination from the ambient are sub-stantially reduced.
In accordance with still another aspect of the invention, there are provided tire pressure communication devices which are reliable in operation, relatively simplistic in design~ readily conducive to implementation of presently existing aircraft, and easily implemented using state-of-the-art apparatus.
An aspect of the invention is as follows:
Apparatus for sensing the pressure of an aircraft tire and for communicating such pressure sensin~ from a rotating tire to a stationary portion of the aircrat, com-prising:
tire pressure sensing means comprising a first set of races connected to and rotatable with the tire;
signal receiving means comprising a second set of races fixedly secured to a stationary portion of the air-craft; and communication means comprising a plurality of ball bearings preloaded between respective pairs or said first and second sets of races, said ball bearings being main-tained between said races in four-point contact for com-municating a signal indicative of tire pressure from said sensing means to said receiving means.
DESCRIPTION OF DRAWINGS
For a complete understanding of the aspects, structure, and techniques of the invention 1 ~1.7g()39
electrical communication from a rotating to a stationary structure.
In accordance with still another aspect of the invention, there is provided a tire pressure communication device wherein tolerance and concentricity problems inci-dent to the prior art are overcome and in which the prior art problems of contamination from the ambient are sub-stantially reduced.
In accordance with still another aspect of the invention, there are provided tire pressure communication devices which are reliable in operation, relatively simplistic in design~ readily conducive to implementation of presently existing aircraft, and easily implemented using state-of-the-art apparatus.
An aspect of the invention is as follows:
Apparatus for sensing the pressure of an aircraft tire and for communicating such pressure sensin~ from a rotating tire to a stationary portion of the aircrat, com-prising:
tire pressure sensing means comprising a first set of races connected to and rotatable with the tire;
signal receiving means comprising a second set of races fixedly secured to a stationary portion of the air-craft; and communication means comprising a plurality of ball bearings preloaded between respective pairs or said first and second sets of races, said ball bearings being main-tained between said races in four-point contact for com-municating a signal indicative of tire pressure from said sensing means to said receiving means.
DESCRIPTION OF DRAWINGS
For a complete understanding of the aspects, structure, and techniques of the invention 1 ~1.7g()39
4.
reference should be had to the following detailed descripti.on and accompanying drawings wherein:
Fig. 1 is an illustrative view oP a first embodiment of the invention utilizing a tire pressure-controlled Bourdon tu~e for regulating a magne.tic gap;
Fig. 2 is a sectional view of another embod-iment of the invention wh~rein tire pressure is used ~or regulating a bellows which in turn controls the core of an LVDT; and Fig. 3 is a sectional view of a commutator made in accordance with the invention utilizing pre-loaded ball bearings for achieving necessary elec-trical communication.
DE:TA:I-LED I)~SC:l~IPTI~N O.F PR}~FER~ED ~IMENTS
Referring now to the drawings and more particularly Fig. 1, it can be seen that a first embodiment of a tire pressure communication device is designated generally by the numeral 10. That device includes a Bourdon tube 12 adapted for interconnec-tion with an aircraft wheel by means of connector straps 14. The connector straps 14 are of a flexible nature and are adaptable ~or centering and maintain-ing the tu~e 12 appropriateIy within a portion of the wheel housing. Flexibility is desired sincel as will be discussed ~mmediately, the diameter o~ the tube 12 fluctuates with tire pressure and, accordingly, the straps 14 must be flexible to maintain ~he tube 12 therewithin.
A standard pressure inlet 15 is provided in communication between the tu~e 12 and the tire. The inlet 15 may pass through the wheel frame and into the envelope defined by the tire and the wheel for making such communication~ Such interconnection is, ~ ~ 7 ~
reference should be had to the following detailed descripti.on and accompanying drawings wherein:
Fig. 1 is an illustrative view oP a first embodiment of the invention utilizing a tire pressure-controlled Bourdon tu~e for regulating a magne.tic gap;
Fig. 2 is a sectional view of another embod-iment of the invention wh~rein tire pressure is used ~or regulating a bellows which in turn controls the core of an LVDT; and Fig. 3 is a sectional view of a commutator made in accordance with the invention utilizing pre-loaded ball bearings for achieving necessary elec-trical communication.
DE:TA:I-LED I)~SC:l~IPTI~N O.F PR}~FER~ED ~IMENTS
Referring now to the drawings and more particularly Fig. 1, it can be seen that a first embodiment of a tire pressure communication device is designated generally by the numeral 10. That device includes a Bourdon tube 12 adapted for interconnec-tion with an aircraft wheel by means of connector straps 14. The connector straps 14 are of a flexible nature and are adaptable ~or centering and maintain-ing the tu~e 12 appropriateIy within a portion of the wheel housing. Flexibility is desired sincel as will be discussed ~mmediately, the diameter o~ the tube 12 fluctuates with tire pressure and, accordingly, the straps 14 must be flexible to maintain ~he tube 12 therewithin.
A standard pressure inlet 15 is provided in communication between the tu~e 12 and the tire. The inlet 15 may pass through the wheel frame and into the envelope defined by the tire and the wheel for making such communication~ Such interconnection is, ~ ~ 7 ~
5.
of course, well ~ithin the capahilities of one skilled in the art. Accordingly, there is communi-cated to the Bourdon tube 12 a pressure correspond-ing to t~e internal pressure of the associated tireO
A magnetic core piece 16, of suitable material for conducting magnetic fluxt is fi~edly secured to a nonrotating portion of the aircraft in ju~taposition to the portion of the wheel maintain-ing the tu~e 12. While t~e actual structure to which the core piece 16 wlll be a~fi2ed will vary from aircraft to aircraft, suita~le places for maintaining t~e same would ~e found on the brake frame, axle, torque tubes, or the like. Suffice i~
to say t~at the core plece 16 is so positioned that a magnetic gap is maintained between the faces of tAe core piece and the Bourdon tube 12 as the wheel carrying the tu~e is rotated.
Connected about the core piece 16 are inductive coils 18,20. One of these coils, in this case coil 18, is an input coil receiving an elec-trical signal from an appropriate signal source on the aircraft. This sïgnal is electromagnetically induced into t~e output core 20, with the signal strength`being controlled b~ the size o~ the magnetic gap existing between the faces of the core 16 and the tube 12~ It will, of sourse, be understood that the tube 12 is metallic or of other ~agnetic flux-conducting material.
In operation, an input signal of fixed signal strength is provided over the input lines to the coil 18. An output signal is induced into the coil 20 and sensed over the output lines 24, with the output sisnal strength being dependent upon the size of t~e magnetic gap or the proximity of the tube 12 to the faces of the core piece 16. Such proximity, or size of the magnetic gap, is directly 1 ~7g(~3~
of course, well ~ithin the capahilities of one skilled in the art. Accordingly, there is communi-cated to the Bourdon tube 12 a pressure correspond-ing to t~e internal pressure of the associated tireO
A magnetic core piece 16, of suitable material for conducting magnetic fluxt is fi~edly secured to a nonrotating portion of the aircraft in ju~taposition to the portion of the wheel maintain-ing the tu~e 12. While t~e actual structure to which the core piece 16 wlll be a~fi2ed will vary from aircraft to aircraft, suita~le places for maintaining t~e same would ~e found on the brake frame, axle, torque tubes, or the like. Suffice i~
to say t~at the core plece 16 is so positioned that a magnetic gap is maintained between the faces of tAe core piece and the Bourdon tube 12 as the wheel carrying the tu~e is rotated.
Connected about the core piece 16 are inductive coils 18,20. One of these coils, in this case coil 18, is an input coil receiving an elec-trical signal from an appropriate signal source on the aircraft. This sïgnal is electromagnetically induced into t~e output core 20, with the signal strength`being controlled b~ the size o~ the magnetic gap existing between the faces of the core 16 and the tube 12~ It will, of sourse, be understood that the tube 12 is metallic or of other ~agnetic flux-conducting material.
In operation, an input signal of fixed signal strength is provided over the input lines to the coil 18. An output signal is induced into the coil 20 and sensed over the output lines 24, with the output sisnal strength being dependent upon the size of t~e magnetic gap or the proximity of the tube 12 to the faces of the core piece 16. Such proximity, or size of the magnetic gap, is directly 1 ~7g(~3~
6.
':
`; dependent upon the t.ire pressure communicated via the inlet 15 to t~e Bourdon tube 12. Accordingly, the signal strengt~ of the output of the coil 20 may be directl.y correlated with tire pressure.
The ~enefît of the ~mbodiment of Fig. 1 is that the core piece 16 may ~e ~ounted inside, out-side, or alongside of the expandible and contract-ible tube 12. Additionally the input coil 18 may be excited with a large current so that small vari-ances in concentricity of the tu~e 12 or in the input ~ignal strength will be relatively unimportant when translated to the output signal of the coil 20.
Further, means ot~er than the Bourdon tu~e 12 might ~e utilized in the general theme of the invention to effectuate a change in the magnetic gap. For exam-ple, the Bourdo~ tu~e 12 could be replaced with a bellows in communication with internal tire pressure, ; such pressure'affectua~ing ~h,e expansion or con~
traction of the bellows which is maintained in juxta- -position with a core piece for regulating a magnetic gap.
' With re~erence now to Fig. 2, it can be seen that a second embodiment of a tire pressure : communica~ion device is designated generally by the numeral 30. Here a wheel frame 32 is pro~ided with a characteristic passageway 34 adapted for co~muni-cating tîre pressure'~rom the. inner cavity of a tire to a bellows 36. The ~ellows, of rubber, flexible plastic, or ot~er suitably expandi~le material, is connected to the movable core 38 of an LVDT. The core 38 is selectïvely positiona~le in the center of coil 40. These cores are connected to a housing 41 which is fi~edly attached to a stationary and non-rotatable mem~er of the aircraft such as an axle, torque tube,' brake housing, or the like. A sleeve or guide 43 is maintained by the housing 41 and is 3~ )39 adapted for receiving th.e core 38. In one embodi-ment of the inventi.on t the core 38 may rotate with the wheel frame 32 in the gulde or slee~e 43. ~he axial position of the core in the center of the coil 40 is controlled by the bellows 36 via tire pr~ssure communicat;ng through the passageway 34~
With continued reference to Fig~ 2, it can be sPen that the sleeve 43 may be characterized by an internal hexagonal ~ore 44. ln this embodiment, the core 38 is characterized by a spherical hex-t agonal head 46 adapted for making mating engagement with the bore 44. A driven mem~er 48 or other appropriate shaft is connected to the guide 43 at one end t~ereof as shbwn. The other end of the driven mem~er 48 may be connected to the rotor of a wheel speed transducer such as those standardly used in antiskid sy~tems in the aircraft industry. In this embodiment, the core 38 rotates with the wheel 32 and, by mea`ns of the mating engagement at 44,46, drives a shaft or other appropriate means 48 for providing a mechanical input signal to a wheel speed transducer.
As briefly mentioned a~o~e, the tire pres-sure communicates to the hellows 36 via the passage-way 34 to longitudinally position the core 38 in the center of the coil 40 of the LVDT. The positionin~
of the core 38 result~ in a particular output signal fxom the LVDT in standard fashion, which signal can be applied to appropriate meter means in the 3Q cockpit. The core 38 may either be freely rotatable within a guid~ or sleeve 43 or, alternatively, may be used for driving a wheel speed transducer through mating interconnection with the guide 43.
With reference now to Fig. 3j it will be noted that yet another embodiment of a tire pressure communication device is designa~ed generally by the 1 ~.790~
8.
numeral 50. This apparatus includes a stationary housing 52 adapted to ~e secure~ t~ a stationary part of the aircrat such as an axle, brake hous-ing, or the like. A ~ushing 54 is provided with appropriate insulators to maintain races 56,57 within the hous;ng 52. A driving arm 58, connected to and rotatable with a wheel (not shown), receiYes an inner portion of each of the races 56,57, while the outer portions thereof are received by the housing 52. Leads 60-66 are interconnected with the races 56,57 with the fixst two such leads being connected to the inner races and rotatable there-with as driven by the arm 58. These leads may be connected to a standard pressure transducer or appropriate pressure sensing means maintained within the tire itself. Communication from the leads 60,62 is made with the leads 64,66 via ball bearings 68 maintained between the inner and outer portions of the races 56,57.
The ball bearings 68 are maintained between the race surfaces as f~ur-point contact bearings which have been preloaded therebetween.
In other words, the inner and outer races are each characterized by "V" grooves such that the ball bearings contact on only two points on each of the "V" surfaces on both the inner and outer race portion. Preloading is accomplished in the stand-ard fashion of thermally assembling the races to achieve forced contacting engagement in a four point pre-loaded manner. Further, the races 56,57 may be packed with a conductive grease serving to both reduce friction and aid in conductivity.
In operation, the leads 60,62 rotate with the inner race portions of the races 56,57 ~5 while the wheel is rotating. The leads 60,62 communicate with the pressure transducer to trans-.
9 ~ ()39 mit an electrical si.gnal ~ack. to the inner race porti.ons which are, in turn t passed across the ball bearings 68 to the outer race portion and thence, by leads 64,66, to appropriate meters in the cockpit.
Of course, a large plurality of ball bear-ings 68 are maintained ~y each of t~e races 56,57 and, with a large plurality of such ball bearings being present, interc~mmunicating with each other on each race by means of conductive grease and by being thermally preloaded, chatter and ~unce are substan-tially el;minated such that the output signal of the pressure monitor is a pure signal as passed to the ~eter.
Thus it can ~e seen that the o~jects of the invention have been satisfied by the structure presented hereina~ove. While in accordance with the patent statutes, only the best modes and preferred embodiments of the lnvention have been presented and descri~ed in detail, it is to be understood that the invention is not limited thereto or thereby.
Consequently, for an appreciation of the true scope `. and breadth of the invention, reference. should be had to the appended claims.
':
`; dependent upon the t.ire pressure communicated via the inlet 15 to t~e Bourdon tube 12. Accordingly, the signal strengt~ of the output of the coil 20 may be directl.y correlated with tire pressure.
The ~enefît of the ~mbodiment of Fig. 1 is that the core piece 16 may ~e ~ounted inside, out-side, or alongside of the expandible and contract-ible tube 12. Additionally the input coil 18 may be excited with a large current so that small vari-ances in concentricity of the tu~e 12 or in the input ~ignal strength will be relatively unimportant when translated to the output signal of the coil 20.
Further, means ot~er than the Bourdon tu~e 12 might ~e utilized in the general theme of the invention to effectuate a change in the magnetic gap. For exam-ple, the Bourdo~ tu~e 12 could be replaced with a bellows in communication with internal tire pressure, ; such pressure'affectua~ing ~h,e expansion or con~
traction of the bellows which is maintained in juxta- -position with a core piece for regulating a magnetic gap.
' With re~erence now to Fig. 2, it can be seen that a second embodiment of a tire pressure : communica~ion device is designated generally by the numeral 30. Here a wheel frame 32 is pro~ided with a characteristic passageway 34 adapted for co~muni-cating tîre pressure'~rom the. inner cavity of a tire to a bellows 36. The ~ellows, of rubber, flexible plastic, or ot~er suitably expandi~le material, is connected to the movable core 38 of an LVDT. The core 38 is selectïvely positiona~le in the center of coil 40. These cores are connected to a housing 41 which is fi~edly attached to a stationary and non-rotatable mem~er of the aircraft such as an axle, torque tube,' brake housing, or the like. A sleeve or guide 43 is maintained by the housing 41 and is 3~ )39 adapted for receiving th.e core 38. In one embodi-ment of the inventi.on t the core 38 may rotate with the wheel frame 32 in the gulde or slee~e 43. ~he axial position of the core in the center of the coil 40 is controlled by the bellows 36 via tire pr~ssure communicat;ng through the passageway 34~
With continued reference to Fig~ 2, it can be sPen that the sleeve 43 may be characterized by an internal hexagonal ~ore 44. ln this embodiment, the core 38 is characterized by a spherical hex-t agonal head 46 adapted for making mating engagement with the bore 44. A driven mem~er 48 or other appropriate shaft is connected to the guide 43 at one end t~ereof as shbwn. The other end of the driven mem~er 48 may be connected to the rotor of a wheel speed transducer such as those standardly used in antiskid sy~tems in the aircraft industry. In this embodiment, the core 38 rotates with the wheel 32 and, by mea`ns of the mating engagement at 44,46, drives a shaft or other appropriate means 48 for providing a mechanical input signal to a wheel speed transducer.
As briefly mentioned a~o~e, the tire pres-sure communicates to the hellows 36 via the passage-way 34 to longitudinally position the core 38 in the center of the coil 40 of the LVDT. The positionin~
of the core 38 result~ in a particular output signal fxom the LVDT in standard fashion, which signal can be applied to appropriate meter means in the 3Q cockpit. The core 38 may either be freely rotatable within a guid~ or sleeve 43 or, alternatively, may be used for driving a wheel speed transducer through mating interconnection with the guide 43.
With reference now to Fig. 3j it will be noted that yet another embodiment of a tire pressure communication device is designa~ed generally by the 1 ~.790~
8.
numeral 50. This apparatus includes a stationary housing 52 adapted to ~e secure~ t~ a stationary part of the aircrat such as an axle, brake hous-ing, or the like. A ~ushing 54 is provided with appropriate insulators to maintain races 56,57 within the hous;ng 52. A driving arm 58, connected to and rotatable with a wheel (not shown), receiYes an inner portion of each of the races 56,57, while the outer portions thereof are received by the housing 52. Leads 60-66 are interconnected with the races 56,57 with the fixst two such leads being connected to the inner races and rotatable there-with as driven by the arm 58. These leads may be connected to a standard pressure transducer or appropriate pressure sensing means maintained within the tire itself. Communication from the leads 60,62 is made with the leads 64,66 via ball bearings 68 maintained between the inner and outer portions of the races 56,57.
The ball bearings 68 are maintained between the race surfaces as f~ur-point contact bearings which have been preloaded therebetween.
In other words, the inner and outer races are each characterized by "V" grooves such that the ball bearings contact on only two points on each of the "V" surfaces on both the inner and outer race portion. Preloading is accomplished in the stand-ard fashion of thermally assembling the races to achieve forced contacting engagement in a four point pre-loaded manner. Further, the races 56,57 may be packed with a conductive grease serving to both reduce friction and aid in conductivity.
In operation, the leads 60,62 rotate with the inner race portions of the races 56,57 ~5 while the wheel is rotating. The leads 60,62 communicate with the pressure transducer to trans-.
9 ~ ()39 mit an electrical si.gnal ~ack. to the inner race porti.ons which are, in turn t passed across the ball bearings 68 to the outer race portion and thence, by leads 64,66, to appropriate meters in the cockpit.
Of course, a large plurality of ball bear-ings 68 are maintained ~y each of t~e races 56,57 and, with a large plurality of such ball bearings being present, interc~mmunicating with each other on each race by means of conductive grease and by being thermally preloaded, chatter and ~unce are substan-tially el;minated such that the output signal of the pressure monitor is a pure signal as passed to the ~eter.
Thus it can ~e seen that the o~jects of the invention have been satisfied by the structure presented hereina~ove. While in accordance with the patent statutes, only the best modes and preferred embodiments of the lnvention have been presented and descri~ed in detail, it is to be understood that the invention is not limited thereto or thereby.
Consequently, for an appreciation of the true scope `. and breadth of the invention, reference. should be had to the appended claims.
Claims (2)
1. Apparatus for sensing the pressure of an aircraft tire and for communicating such pressure sensing from a rotating tire to a stationary portion of the aircraft, com-prising:
tire pressure sensing means comprising a first set of races connected to and rotatable with the tire;
signal receiving means comprising a second set of races fixedly secured to a stationary portion of the air-craft; and communication means comprising a plurality of ball bearings preloaded between respective pairs of said first and second sets of races, said ball bearings being main-tained between said races in four-point contact for com-municating a signal indicative of tire pressure from said sensing means to said receiving means.
tire pressure sensing means comprising a first set of races connected to and rotatable with the tire;
signal receiving means comprising a second set of races fixedly secured to a stationary portion of the air-craft; and communication means comprising a plurality of ball bearings preloaded between respective pairs of said first and second sets of races, said ball bearings being main-tained between said races in four-point contact for com-municating a signal indicative of tire pressure from said sensing means to said receiving means.
2. The apparatus according to claim 1 wherein said ball bearings within said races are maintained within an electrically conductive grease.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000440135A CA1179039A (en) | 1979-07-30 | 1983-10-31 | Tire pressure communication devices |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/061,580 US4237445A (en) | 1979-07-30 | 1979-07-30 | Tire pressure communication devices |
| US61,580 | 1979-07-30 | ||
| CA000352948A CA1175125A (en) | 1979-07-30 | 1980-05-29 | Tire pressure communication devices |
| CA000440135A CA1179039A (en) | 1979-07-30 | 1983-10-31 | Tire pressure communication devices |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000440135A Division CA1179039A (en) | 1979-07-30 | 1983-10-31 | Tire pressure communication devices |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000440135A Division CA1179039A (en) | 1979-07-30 | 1983-10-31 | Tire pressure communication devices |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1179039A true CA1179039A (en) | 1984-12-04 |
Family
ID=27166694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000440135A Expired CA1179039A (en) | 1979-07-30 | 1983-10-31 | Tire pressure communication devices |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1179039A (en) |
-
1983
- 1983-10-31 CA CA000440135A patent/CA1179039A/en not_active Expired
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