Valve Position Indicators
20220154845 · 2022-05-19
Inventors
Cpc classification
F16K5/187
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K31/5284
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K11/0873
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K31/60
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K37/0083
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K5/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K5/163
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K37/0041
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K31/54
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H01H3/16
ELECTRICITY
F16K31/524
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K37/0058
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16K31/528
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K31/524
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K31/54
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K31/60
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K37/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16K5/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A rotational valve includes a valve closure element, a shaft, at least one detection element, at least one detection engagement means, at least one first stop and at least one second stop. The shaft is linked to the valve closure element and the shaft can rotate between a closed position and a fully open position. Each detection element comprises an aperture and an indicator element, the shaft extends through the aperture of at least one detection element, and each detection element is in sliding engagement with the shaft. The shaft can rotate relative to the detection element, each indicator element can move between a first and a second indicator position, each indicator element abuts a first stop when in the first indicator position and abuts a second stop when in the second indicator position.
Claims
1. A rotational valve comprising: a valve closure element; a shaft is linked to the valve closure element, wherein the shaft can rotate between a closed position and a fully open position; at least one detection element, each detection element comprises an aperture and an indicator element; and at least one first stop and at least one second stop; wherein; the shaft extends through the aperture of at least one detection element, wherein each of the at least one elements is in sliding engagement with the shaft (22); the shaft can rotate relative to each of the at one detection elements; each indicator element can move between a first and a second indicator position; each indicator element abuts the first stop when in the first indicator position and abuts the second stop when in the second indicator position; each indicator element is associated with a detection engagement means; each detection engagement means can determine when it's associated indicator element is in one of the first or second indicator positions; and each detection element is configured to engage with the shaft via at least one engagement mechanism when the rotational position of the shaft relative to the shaft's closed position is in a predetermined angular range.
2. The rotational valve according to claim 1, wherein the valve (2) comprises: at least two detection elements; wherein each of the detection elements engages with the shaft when the rotational position of the shaft relative to the shaft's closed position is in a predetermined angular range and that angular range is different for each detection element.
3. The rotational valve according to claim 1, wherein each engagement mechanism comprises: a shaft engagement means associated with the shaft; and a detection engagement means associated with a detection element; wherein engagement of the shaft and detection engagement means enables the shaft to transmit rotational torque to the detection element via the shaft and detection engagement means; and wherein the shaft and detection engagement means are configured such that if rotation of the detection element is resisted by a force greater in magnitude than a disengagement force the shaft and detection engagement means will disengage from each other.
4. The rotational valve according to claim 3, wherein: at least one of the is associated with a first and a second engagement mechanism; the shaft and detection engagement means of the first engagement mechanism are dimensioned and configured so that they engage with each other when the shaft is rotating in a first direction and do not engage with each other when the shaft is rotating in the opposite second direction; and the shaft and detection engagement means of the second engagement mechanism are dimensioned and configured so that they engage with each other when the shaft is rotating in the second direction and do not engage with each other when the shaft is rotating in the first direction.
5. The rotational valve according to claim 4, wherein in at least one engagement mechanism the shaft engagement means is a male engagement means and the detection engagement means is a female engagement means, or the shaft engagement means is a female engagement means and the detection engagement means is a male engagement means.
6. The rotational valve according to claim 5, wherein the male engaging means comprises: a cavity; a biasing element; and an upstanding element; wherein: the cavity is defined by a cavity base and one or more walls; the cavity, the biasing element and the upstanding element are dimensioned and configured that the cavity may contain the biasing element and the upstanding element; the biasing element biases the upstanding element at least partially out of the cavity; the upstanding element may reversibly move between a first position in which it is at least substantially wholly within the cavity, and a second position in which at least a portion of the upstanding element extends out of the cavity; and the one or more walls of the cavity can engage with the upstanding element to resist forces exerted on the upstanding element in a direction perpendicular to the direction of movement of the upstanding element (76) between the first and second positions.
7. The rotational valve according to claim 6, in which at least one female engaging means comprises a circumferentially extending slot, in which the axial width and radial depth of the slot are sufficient to allow at least a portion of the male engagement means to enter the slot and move along the circumferential length of the slot.
8. The rotational valve according to claim 7, wherein the male engagement means and at least one end of the circumferentially extending slot are so configured that when the male engagement means abuts the at least one end of the circumferentially extending slot and rotation of the detection element is resisted by a force less than the disengagement force, torque from the shaft is transmitted to the detection element through the abutment of the male engagement means and the at least one end of the circumferentially extending slot.
9. The rotational valve according to claim 8, wherein one end of the circumferentially extending slot is so configured that travel of the male engagement member along the slot toward that end and subsequently out of the slot does not transmit any torque from the shaft to the detection element when the rotation of the detection element is resisted by a force less than the disengagement force.
10. The rotational valve according to claim 1, wherein the one or more detection engagement means comprises a mechanical switch, an optical sensor, a hall effect sensor, or an ultrasonic sensor
11. The rotational valve according to claim 1, further comprising: an actuation means, wherein actuation of the actuation means rotates the shaft and causes rotation of the closure element or actuation of the actuation means rotates the closure element and causes rotation of the shaft.
12. The rotational valve according to claim 11, wherein the actuation means comprises an electrically powered motor.
13. The rotational valve according to claim 1, further comprising: an enclosure, wherein the enclosure at least partially surrounds the shaft, detection elements, indicator elements and detection engagement means.
14. A potable water system for an aircraft comprising: at least one rotational valve according to claim 1.
15. A method for determining the position of a valve closure element within a rotational valve comprising: use of a valve according to claim 1; and with an interpretation means, converting signals received from the detection means to a signal signifying the position of the valve closure element.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] The present disclosure will be further described and explained by way of example and with reference to the accompanying drawings in which:
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DETAILED DESCRIPTION
[0067] With reference to
[0068] The valve 2 is a shut off valve has a valve body 8 to which the conduits 4A, 4B are attached via inlet and outlet ports 10, 12. Within the valve body 8 is a passage 14 extending between and in fluid communication with inlet and outlet ports 10, 12. Approximately midway along the passage 14 is a valve chamber 16. Within the valve chamber 16 is a closure element 18 which has the form a substantially complete sphere with a passage 20 passing through the sphere 18. The closure element 18 is in sliding and sealing contact with the wall defining the valve chamber 16 and may rotate about axis A. The closure element 18 may rotate between a position in which the passage 20 is in complete alignment and co axial with the passage 14, to be referred to as the valve fully open position, and a position in which the passage 20 is wholly out of alignment with the passage 20 and there is no fluid communication between the passages 14 and 20, to be referred to as the valve closed position.
[0069] In a second non-illustrated embodiment of the present invention the valve is a configurable channel flow valve and has a valve body to which three conduits are attached via an inlet and two outlet ports. Within the valve body is a bifurcated passage extending between and in fluid communication with the inlet and two outlet ports. Approximately midway along the passage is a valve chamber. Within the valve chamber is a closure element which has the form a substantially complete sphere with a suitably shaped channel passing through the sphere. In some embodiments the channel is T-shaped as schematically illustrated in
[0070] A shaft 22 is fixed to the closure element 18 at a location and with an orientation such that the central axis of shaft 18 is coincides with the axis A. The shaft 22 extends between the closure element 18 and an electrically powered motor 24. The motor 24 is so configured that it can rotate the shaft and closure element in either direction around the central axis A and can do so for small steps or small rotational angles around the axis A.
[0071] In some, unillustrated, embodiments of the present disclosure the there is a rotation reducing means such as gearing between the motor 24 and the shaft 22 so that rotation of the motor 24 by a certain angle of rotation, for example 40 degrees causes 10 degrees of rotation of the shaft 22.
[0072] An enclosure 26 surrounds a part of the shaft 22 and the locator detector means of the valve 2. The enclosure protects the location detector means 28.
[0073] With reference to
[0074] The enclosure 26 is attached to the valve body 8 by means not shown, Such means may be known fixing means such as bolts extending into a threaded bore in the valve body 8. The enclosure 26 defines a first void 34 which is configured to surround a portion of the detection elements 30. The first void 34 is so dimensioned that the radially outer face of the detection elements 32 is in close proximity to or in sliding engagement with the face 36 of the enclosure defining the void 34.
[0075] The enclosure 26 also defines a second void 38. Second void 38 is configured to both allow movement of indicator element 32 when rotating around axis A, and to house a number of detector means 44. The second void 38 is in part defined by a stop face 40 and a mounting face 42.
[0076] The mounting face 42 of the enclosure 26 is adapted to have three detector means 44 attached to that face by known means (not shown). In one example, the attachment means is an adhesive.
[0077] In the example shown in
[0078] As shown in
[0079] The indicator element 32 may rotate clockwise from the first indicator position 55 (as seen in
[0080] Each detection element 30 includes an aperture 64 substantially defined by an aperture face 66. The aperture face 66 is configured and dimensioned to overlie a portion of the radially outer face of the shaft 22 and to allow the shaft to rotate about the axis A relative to the detection element 30 with the surface of the shaft in sliding contact with the aperture face. The detection elements 30 may be impelled to rotate around the axis A by the transmission of torque from the shaft 22 to the detection element 30 via one or more engagement mechanisms.
[0081] Each engagement mechanism is made up of a shaft engagement means 60 and a detection engagement means 62. With reference to
[0082] Within the cavity 68 is a biasing element 74 and an upstanding element 76. The biasing element 74 biases the upstanding element 76 so that the radially outer part of the upstanding element extends out of the cavity 68 as is shown in
[0083] The upstanding element 76 has a substantially hemispherical radially outer end 70 and a radially inner end 80 that is substantially cylindrical (labelled only in
[0084] The biasing element 74 is located between the cavity base 70 and the radially inner end 82 of upstanding element 76. The biasing element 74 is a helical spring. The helical spring is so dimensioned that in its relaxed, non-deformed, condition the radially outer end 78 of the upstanding element 76 projects above the surface of the shaft 22 as shown in
[0085] The shaft engagement means may include elements (not shown) that prevent the upstanding element 76 fully leaving the cavity 68.
[0086] The shell 102 of the spring plunger 60 has an external thread allowing it to be screwed into threaded bores (not shown) in the shaft 22.
[0087] With reference to
[0088] Each slot base 88 intersects the end face 86A/86B associated with that slot base at an included angle that is at least 90 degrees and preferably greater than 90 degrees and less than 150 degrees. The slot base 88 is curved along its length and the end of the slot base 88 remote from the end face 86A/86B intersects the radially inner face 66 of the detection element at position 98A/98B at an angle of less than 15 degrees to the tangent to the face 66 at position 98A/98B.
[0089] The first and second detection element means are so configured that the end faces 86A and 86B are separated by an uninterrupted portion of radially inner face 66. Alternatively expressed, for one of the detection engagement means 62 movement from position 98A to the end face 86A is clockwise movement and movement from position 98B to 86B is anti-clockwise. Clockwise and anti-clockwise are relative to axis A and as shown in
[0090] With reference to
[0091] Each slot base 96 intersects the end faces 94A, 94B associated with that slot base at an included angle that is at least 90 degrees and preferably greater than 90 degrees and less than 150 degrees. The slot base 96 is curved along its length and describes an arc around the axis A.
[0092] With further reference to
[0093] The shaft is provided with a pair of spring plunger/shaft engagement means 60 for each detection element. The shaft engagement means 60 are located diametrically opposite to each other on the shaft. The pairs of shaft engagement means 60 are axially spaced along the shaft 22,
[0094]
[0095] Rotation of the shaft 22 in a clockwise direction to the position shown in
[0096] Continued clockwise rotation of the shaft 22 causes the upstanding elements 74 to travel along the slots of the detection engagement means 62 until upstanding elements 76 abut end faces 94B. When the detection element 30 is orientated as shown in
[0097] When the indicator element 32 reaches the second indicator position 58 the resistance to clockwise rotation of the detection element 30 very rapidly increases. The resistance to rotation very rapidly reaches the disengagement force and the radial vector of the force transmitted from the end face 94B to the upstanding element 74 exceeds the spring force of the biasing element 74. At that time the upstanding element 74 is pushed into the cavity 68 and the shaft 22 can then continue to rotate in a clockwise direction as shown in
[0098] When the shaft 22 rotates in an anti-clockwise direction, the same series of events takes place with the exception that the upstanding element 74 abuts end face 94A rather than 94B.
[0099] With further reference to
[0100] The shaft is provided with a pair of spring plungers/shaft engagement means 60A, 60B for each detection element. The shaft engagement means 60A, 60B are located diametrically opposite to each other on the shaft. The pairs of shaft engagement means 60A, 60B are axially spaced along the shaft 22,
[0101]
[0102] Rotation of the shaft 22 in a clockwise direction to the position shown in
[0103] Continued clockwise rotation of the shaft 22 causes the upstanding element 74 of shaft engagement means 60A to travel along the slot of the detection engagement means 62A with the upstanding elements 74 moving toward its first position as the slot of detection engagement means 62A deepens. When the upstanding element 74 abuts end 86A it is in its first position. At the same time, the upstanding element 76 of shaft engagement means 60B travels along the slot of the detection engagement means 62B. That motion causes the upstanding element 76 of shaft engagement means 60B to be forced toward it's second position and biasing element 74 to be compressed as the slot of detection engagement means 62B becomes shallower.
[0104] When the detection element 30 is orientated as shown in
[0105] When the indicator element 32 reaches the second indicator position 58 the resistance to clockwise rotation of the detection element 30 very rapidly increases. The resistance to rotation very rapidly reaches the disengagement force and the radial vector of the force transmitted from the end face 86A to the upstanding element 76 of shaft engagement means 60A exceeds the spring force of the biasing element 74. At that time the upstanding element 76 is pushed into the cavity 68. At the same time, the shaft engagement means 60B is close to position 98 and the upstanding element 76 in its second positon within its cavity 68 and shaft 22 can then continue to rotate in a clockwise direction as shown in
[0106] When the shaft 22 rotates in an anti-clockwise direction, the same series of events takes place with the exception that the upstanding element 74 of shaft engagement means 60B abuts end face 86B rather than shaft engagement means 60A abutting end face 86A.
[0107] With reference to
[0108] In all other senses, the embodiment of the valve 2 shown in
[0109] With reference to
[0110] The valve is so configured that switch 1 is closed when the closure element 18 is in position 0 for example fully open, and switches 1, 2, and 3 are closed when the closure element 18 is in position 3 for example fully closed.
[0111] When the closure element 18 is in position 0, a high input (current) is received in the AND gate 212 from the input voltage source 208. The NOT gate 210 has a low input because the switch 1 is open. As a result, the NOT gate 210 outputs a high output which is input into the AND gate 212. The AND Gate 212, receiving two high inputs, generates a high output and allows current to flow in wire U and an indicator means shows or reports that the that closure element 18 is in position 0.
[0112] When the closure element 18 is in position 1 switch 1 is closed and switches 2 and 3 are open. As a result, the NOT gate 210 receives a high input and thus generates a low output. The low output is input into the AND gate 212 and the indicator means which shows or reports that the that closure element 18 is in position 0 is not activated. A high input (current) passes from switch 1 to the AND gate 214. A high input to the AND gate 214 is generated by the NOT gate 220 because switch 2 is open meaning the NOT gate 220 has a low input (no current) and thus generates a high output which is an input to the AND Gate 214. The AND gate 214 accordingly generates a high output and allows current to flow in wire W and an indicator means shows or reports that the that closure element 18 is in position 1.
[0113] When the closure element 18 is in position 2 switches 1 and 2 are closed and switch 3 is open. As a result, a high input passes from switch 1 to the AND gate 214. The NOT gate 220 generates a low output and hence low input to the AND gate 214 because switch 2 is closed (meaning switch 2 generates a high output which is received by the NOT gate 220 causing a low output from the NOT gate 220 to the AND Gate 214). The AND gate 214 accordingly generates a low output and does not allow current to flow in wire W and the indicator means that shows or reports that the that closure element 18 is in position 1 is not activated. The high output from switch 2 is also the input for the AND gate 216. A high output is also generated by the NOT gate 222 and input to the AND gate 216 because switch 3 is open meaning there is a low input to the NOT gate 222 and thus a high output is generated by the NOT gate 222. That high output is input to the AND Gate 216. The AND gate 216 accordingly generates a high output which allows current to flow in wire X and an indicator means shows or reports that the that closure element 18 is in position 2.
[0114] When the closure element 18 is in position 3 switches 1, 2 and 3 are closed. As a result, a high input passes from switch 1 to the AND gate 214. The NOT gate 220 generates a low output and hence low input to the AND gate 214 because switch 2 is closed (meaning switch 2 generates a high output which is received by the NOT gate 220 causing a low output from the NOT gate 220 to the AND Gate 214). The AND gate 214 accordingly generates a low output and does not allow current to flow in wire W and the indicator means that shows or reports that the that closure element 18 is in position 1 is not activated. The high output from switch 2 is also the input for the AND gate 216. A high output is also generated by the NOT gate 222 and input to the AND gate 216 because switch 3 is open meaning there is a low input to the NOT gate 222 and thus a high output is generated by the NOT gate 222. That high output is input to the AND Gate 216. The AND gate 216 accordingly generates a high output which allows current to flow in wire X and the indicator means which shows or reports that the that ball shaft 204 is in position 2 is not activated. Switch 3 generates a high output which is the input to both inputs of the AND gate 218 and as a result the AND gate 218 generates a high output and allows current to flow in wire Y and an indicator means shows or reports that the that closure element 18 is in position 3.
[0115] With reference to
[0116] The position determining circuit 200 functions as described in connection with
[0117] In the error sensing circuit 226, when the closure element 18 is in position 2 the output from switches 1 and 2 should both be high and the output from switch 3 should be low. If that is the situation then the high input from switch 1 to the NOT gate 230 will cause a low output from the NOT gate 230 into the AND gate 236. The high input from switch 2 will input into the AND gate 236 via the OR gate 234, and the AND gate 236 will generate a low output. If, however, the switch 1 is not generating a high output then the NOT gate 230 will generate a high output which will input into the AND gate 236 resulting in a high output which will, via the OR gate 238 cause current to flow in wire Z and activate the error indicator.
[0118] In a similar fashion, when the closure element 18 is in position 3 all of switches 1,2, and 3 should have a high output. If switch 1 does not then as discussed above the error indicator is activated. Additionally or alternatively, if switch 2 is not generating a high output and switches 1 and 3 are generating high outputs, the NOT gate 232 will generate a high output which inputs into the AND gate 244. The other input to the AND gate 244 is the switch 1 and as a result the AND gate 244 will generate a high output output which will, via the OR gate 238 cause current to flow in wire Z and activate the error indicator.
[0119] With reference to
[0120] The position determining circuit 200 functions as described in connection with
[0121] The false signal blocker circuit 248 has the effect that as long as the error sensing circuit 226 is not sensing an error, the input to the NOT gate 252 is a low input resulting in a high output. That high output is an input to each of AND gates 260, 254, 256 and 258 which respectively have a second input from input voltage source 208, and AND gates 214, 216 and 218. As a result, the AND gates 260, 254, 256 and 258 will output a high output when the position determining circuit is determining the position of the closure element 18, and the error sensing circuit 226 is not sensing errors. If the error sensing circuit 226 senses an error, then the input to the NOT gate 252 is high and thus the input into AND gates 260, 254, 256 and 258 from the NOT gate 238 is low and no positions will be indicated for the closure element 18. The reader of the position indicators can then not be potentially mislead as to the position of the closure element 18.
[0122] With regard to
[0123]
[0124] The ball shaft 104 can be rotated between position where the channel allows fluid communication from the inlet 112 to both of the outlets 108, 110 (where the ball shaft 104 has a rotational position of about 88-92 degrees) as shown in
[0125] With reference to
[0126] The valve is so configured that switch 1 is closed when the ball shaft 104 is in position 1′ for example the position shown in
[0127] When the ball shaft 104 is in position 1′ switch 1 is closed and switches 2 and 3 are open. As a result, a high input (current) passes from switch 1 to the AND gate 114. A high input to the AND gate 114 is generated by the NOT gate 120 because switch 2 is open meaning the NOT gate 120 has a low input (no current) and it thus generates a high output which is an input to the AND Gate 114. The AND gate 114 accordingly generates a high output and allows current to flow in wire W and an indicator means shows or reports that the that ball shaft 104 is in position 1′.
[0128] When the ball shaft 104 is in position 2′ switches 1 and 2 are closed and switch 3 is open. As a result, a high input passes from switch 1 to the AND gate 114. The NOT gate 120 generates a low output and hence low input to the AND gate 114 because switch 2 is closed (meaning switch 2 generates a high output which is received by the NOT gate 120 causing a low output from the NOT gate 120 to the AND Gate 114). The AND gate 114 accordingly generates a low output and does not allow current to flow in wire W and the indicator means that shows or reports that the that ball shaft 104 is in position 1′ is not activated. The high output from switch 2 is also the input for the AND gate 116. A high output is also generated by the NOT gate 122 and input to the AND gate 116 because switch 3 is open meaning there is a low input to the NOT gate 122 and thus a high output is generated by the NOT gate 122. That high output is input to the AND Gate 116. The AND gate 116 accordingly generates a high output which allows current to flow in wire X and an indicator means shows or reports that the that ball shaft 104 is in position 2′.
[0129] When the ball shaft 104 is in position 3′ switches 1, 2 and 3 are closed. As a result, a high input passes from switch 1 to the AND gate 114. The NOT gate 120 generates a low output and hence low input to the AND gate 114 because switch 2 is closed (meaning switch 2 generates a high output which is received by the NOT gate 120 causing a low output from the NOT gate 120 to the AND Gate 114). The AND gate 114 accordingly generates a low output and does not allow current to flow in wire W and the indicator means that shows or reports that the that ball shaft 104 is in position 1′ is not activated. The high output from switch 2 is also the input for the AND gate 116. A high output is also generated by the NOT gate 122 and input to the AND gate 116 because switch 3 is open meaning there is a low input to the NOT gate 122 and thus a high output is generated by the NOT gate 122. That high output is input to the AND Gate 116. The AND gate 116 accordingly generates a high output which allows current to flow in wire X and the indicator means which shows or reports that the that ball shaft 104 is in position 2′ is not activated. Switch 3 generates a high output which is the input to both inputs of the AND gate 118 and as a result the AND gate 118 generates a high output and allows current to flow in wire Y and an indicator means shows or reports that the that ball shaft 104 is in position 3′.
[0130] With reference to
[0131] The position determining circuit 100 functions as described in connection with
[0132] In the error sensing circuit 126, when the ball shaft 104 is in position 2′ the output from switches 1 and 2 should both be high and the output from switch 3 should be low. If that is the situation then the high input from switch 1 to the NOT gate 130 will cause a low output from the NOT gate 130 into the AND gate 136. The high input from switch 2 will input into the AND gate 136 via the OR gate 134, and the AND gate 136 will generate a low output. If, however, the switch 1 is not generating a high output then the NOT gate 130 will generate a high output which will input into the AND gate 136 resulting in a high output which will, via the OR gate 138 cause current to flow in wire Z and activate the error indicator.
[0133] In a similar fashion, when the ball shaft 104 is in position 3′ all of switches 1,2, and 3 should have a high output. If switch 1 does not then as discussed above the error indicator is activated. Additionally or alternatively, if switch 2 is not generating a high output and switches 1 and 3 are generating high outputs, the NOT gate 132 will generate a high output which inputs into the AND gate 144. The other input to the AND gate 144 is the switch 1 and as a result the AND gate 144 will generate a high output which will, via the OR gate 138 cause current to flow in wire Z and activate the error indicator.
[0134] With reference to
[0135] The position determining circuit 100 functions as described in connection with
[0136] The false signal blocker circuit 148 has the effect that as long as the error sensing circuit 126 is not sensing an error, the input to the NOT gate 152 is a low input resulting in a high output. That high output is an input to each of AND gates 154, 156 and 158 which respectively have a second input from AND gates 114, 116 and 118. As a result, the AND gates 154, 156 and 158 will output a high output when the position determining circuit is determining the position of the ball shaft 104, and the error sensing circuit 126 is not sensing errors. If the error sensing circuit 126 senses an error, then the input to the NOT gate 152 is high and thus the input into AND gates 154, 156 and 158 from the NOT gate 138 is low and no positions will be indicated for the ball shaft 104. The reader of the position indicators can then not be potentially mislead as to the position of the ball shaft 104.
[0137] With regard to
[0138] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure.
[0139] Various aspects of the valves disclosed in the various embodiments may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described above. This disclosure is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments. Although particular embodiments have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects. The scope of the following claims should not be limited by the embodiments set forth in the examples, but should be given the broadest reasonable interpretation consistent with the description as a whole.