Switching apparatus

Claim 2

A switching apparatus comprising: an actuator which is displacable by contact with an object to at least first and second displacement positions; first detecting means for producing a first detection output when said first displacement position of the actuator is detected; second detecting means for producing a second detection output when said second displacement position of the actuator is detected, said first and second detection outputs being produced in sequence; means for generating a switch output when at least one of said first and second detection outputs is produced; and abnormality detecting means for detecting an abnormality based on at least one of the first and second detection outputs of said first and second detecting means, said abnormality detecting means comprising a clocking means for providing a clocking signal indicating a time lapse from a time point when one of said first and second detection outputs is produced and a checking means for checking whether the detection states of the first and second detecting means are a predetermined state responsive to said clocking means measuring a predetermined time lapse after said time point when said one of said first and second detection outputs is produced.

Claim 3

A switching apparatus according to claim 1, wherein said first detecting means is a first switch which is switched to the on state or the off state in association with the displacement of the actuator, said second detecting means is a second switch which is switched to the on state or the off state later than said first switch in association with the displacement of the actuator; said means for generating a switch output comprising a switch output circuit for generating the switch output when one of said first and second switches is in the on state and the other of said first and second switches is in the off state, and said abnormality detecting means comprises a failure predicting circuit which detects an abnormality of either of said first and second switches on the basis of the on and off states of said first and second switches and which outputs a failure prediction signal.

Claim 4

A switching apparatus according to claim 1, wherein said first detecting means is a switch which is switched to the on state or the off state in association with the displacement of the actuator, said second detecting means is a contact detecting means for detecting that an object is touching the actuator or a member which is interlocked therewith, said means for generating a switch output comprising a switch output circuit for generating the switch output when at least one of the on state or off state of said switch is detected and the contact of the object by said contact detecting means is detected, and at least one of the off state or on state of said switch is detected and removal of the object by said contact detecting means is detected, and said abnormality detecting means comprises a failure predicting circuit which detects an abnormality of either of said switch and said contact detecting means based on the on and off states of said switch and the contact detecting state by said contact detecting means, and which outputs a failure prediction signal.

Claim 5

A switching apparatus comprising: an actuator which is displacable by contact with an object to at least first and second displacement positions; first detecting means for producing a first detection output when said first displacement position of the actuator is detected; second detecting means for producing a second detection output when said second displacement position of the actuator is detected; means for generating a switch output when at least one of said first and second detection outputs is produced; and abnormality detecting means for detecting an abnormality based on at least one of the first and second detection outputs of said first and second detecting means; wherein said first detecting means and said means for generating a switch output are formed by a displacement sensor which detects a displacement amount of the actuator and switching means for generating the switch output when a predetermined operation displacement amount less than a normal displacement amount which is detected by said displacement sensor in a normal operational state is detected by said displacement sensor, and said second detecting means and said abnormality detecting means are formed by said displacement sensor and a failure predicting means for comparing a final displacement amount detected by said displacement sensor with a predetermined final normal displacement amount and for outputting a failure prediction signal when the difference between the final displacement amount and the final normal displacement amount is above a predetermined value.

Claim 6

A switching apparatus comprising: an actuator which is displacable by contact with an object to at least first and second displacement positions; first detecting means for producing a first detection output when said first displacement position of the actuator is detected; second detecting means for producing a second detection output when said second displacement position of the actuator is detected; means for generating a switch output when at least one of said first and second detection outputs is produced; and abnormality detecting means for detecting an abnormality based on at least one of the first and second detection outputs of said first and second detecting means; wherein said first detecting means and said means for generating a switch output are formed by a displacement sensor which detects a displacement amount of the actuator and switching means for generating the switch output when a predetermined operation displacement amount less than a normal displacement amount which is detected by said displacement sensor in a normal operational state is detected by said displacement sensor, and said second detecting means and said abnormality detecting means are formed by said displacement sensor and a failure predicting means for comparing a final displacement amount detected by said displacement sensor with a predetermined final normal displacement amount and for outputting a failure prediction signal when the difference between the final displacement amount and the final normal displacement amount is above a predetermined value.

Claim 7

A switching apparatus comprising: an actuator which causes a displacement by a contact with an object; a first switch which is switched to the on state or the off state in association with a displacement of the actuator; a second switch which is switched to the on state or the off state later than said first switch in association with the displacement of the actuator; state detecting circuits which detect the on state and the off state of said first and second switches; a switch output circuit which generates a switch output based on the on state of one of said first and second switches and the off state of the other of said first and second switches in response to output signals of said state detecting circuits; and a failure predicting circuit which detects an abnormality of either of said first and second switches based on the outputs of said state detecting circuits and which outputs a failure prediction signal.

Claim 8

A switching apparatus comprising: an actuator which causes a displacement by a contact with an object; a first switch which is switched to the on state or the off state in association with a displacement of the actuator; a second switch which is switched to the on state or the off state later than said first switch in association with the displacement of the actuator; state detecting circuits which detect the on state and the off state of said first and second switches; a switch output circuit which generates a switch output based on the on state of one of said first and second switches and the off state of the other of said first and second switches in response to output signals of said state detecting circuits; and a failure predicting circuit which detects an abnormality of either of said first and second switches based on the outputs of said state detecting circuits and which outputs a failure prediction signal.

Claim 9

A switching apparatus comprising: an actuator which causes a displacement by a contact with an object; a switch which is switched to the on state or the off state in association with a displacement of the actuator; contact detecting means for detecting that the object is touching the actuator or a member which is interlocked therewith; state detecting circuits which detect the on state and the off state of said switch and the contact state and the removal state of the object with and from said contact detecting means; a switch output circuit which generates a switch output on the basis of at least one of the detection of the on state or off state of said switch and the contact detection by said contact detecting means, and at least one of the detection of the off state or on state of said switch and the removal detection by said contact detecting means in response to outputs of said state detecting circuits; and a failure predicting circuit which detects an abnormality of either of said switch and said contact detecting means based on the outputs of said state detecting circuits and which outputs a failure prediction signal.

Claim 10

A switching apparatus comprising: an actuator which causes a displacement by a contact with an object; a switch which is switched to the on state or the off state in association with a displacement of the actuator; contact detecting means for detecting that the object is touching the actuator or a member which is interlocked therewith; state detecting circuits which detect the on state and the off state of said switch and the contact state and the removal state of the object with and from said contact detecting means; a switch output circuit which generates a switch output on the basis of at least one of the detection of the on state or off state of said switch and the contact detection by said contact detecting means, and at least one of the detection of the off state or on state of said switch and the removal detection by said contact detecting means in response to outputs of said state detecting circuits; and a failure predicting circuit which detects an abnormality of either of said switch and said contact detecting means based on the outputs of said state detecting circuits and which outputs a failure prediction signal.

Claim 11

A switching apparatus comprising: an actuator which causes a displacement by a contact with an object; a displacement sensor which detects a displacement amount of the actuator; switching means for generating a switch output when a predetermined operation displacement amount less than a normal displacement amount which is detected by said displacement sensor in a normal operational state is detected by said displacement sensor; and failure predicting means for comparing a final displacement amount detected by said displacement sensor with a predetermined final normal displacement amount and for outputting a failure prediction signal when the difference between the final displacement amount and the final normal displacement amount is greater than or equal to a predetermined value.

Claim 12

A switching apparatus comprising: an actuator which causes a displacement by a contact with an object; a displacement sensor which detects a displacement amount of the actuator; switching means for generating a switch output when a predetermined operation displacement amount less than a normal displacement amount which is detected by said displacement sensor in a normal operational state is detected by said displacement sensor; and failure predicting means for comparing a final displacement amount detected by said displacement sensor with a predetermined final normal displacement amount and for outputting a failure prediction signal when the difference between the final displacement amount and the final normal displacement amount is greater than or equal to a predetermined value.