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US 4,543,000 AGranted
Latching actuator
OwnerRalph D. Hasenbalginventor
Life of this patent
Estimating the term…
Abstract
A keyboard actuator for actuating the keys of a keyboard-operated apparatus including a plurality of fluid latching actuators supported to controllably and selectively actuate a key. In the preferred embodiment, each fluid actuator includes a latch and a piston. In response to fluid pressure, the latch releases the piston and the piston may be driven to actuate a key of the keyboard-operated apparatus. No return spring is used to cause a piston rod to rise to a position where it can be latched. The upward action of normally operative key effects the return of the piston rod to achieve latching.
Claims6
A latching fluid actuator for testing the action of keys of a keyboard comprising:
- a cylinder closed at one end and a piston member sealably carried within the cylinder, the piston member including a piston rod, the rod at its one end being arranged to move downwardly to contact a key to be tested, and engagement means,
- first fluid inlet means for providing fluid communication through the cylinder closed end,
- a latch element having a first member and a second member disposed on opposite sides of the piston rod and a third member interconnecting the first and second members,
- a fluid responsive diaphragm member acting against one of the first or second members of the latch element,
- second fluid inlet means for providing fluid communication to the fluid responsive member, said second fluid inlet means providing a fluid communication independent of the fluid communication to the first fluid inlet means,
- spring means for applying biasing force against the other of the first or second members of the latch element, the second member being adapted to engage the piston member engagement means, the engagement means being for receiving the second member to prevent piston member displacement, and
- the cylinder being free of a return spring member such that the upward action of a normally operative key effectively returns the piston rod upwardly to a position where the second member is permitted to engage the engagement means.
4 more elements
A latching fluid actuator for testing the action of keys of a keyboard comprising:
- a cylinder closed at one end and a piston member sealably carried within the cylinder, the piston member including a piston rod, the rod at its one end being arranged to move downwardly to contact a key, and engagement means,
- first fluid inlet means for providing fluid communication through the cylinder closed end,
- a latch element having a first member and a second member disposed on opposite sides of the piston rod and a third member interconnecting the first and second members;
- a fluid responsive diaphragm member acting against one of the first or second members of the latch element,
- second fluid inlet means for providing fluid communication to the fluid responsive member, said second fluid inlet means providing a fluid communication independent of the fluid communication to the first fluid inlet means, and
- spring means for applying biasing force against the other of the first or second members of the latch element, the second member being adapted to engage the piston member engagement means, the engagement means being for receiving the second member to prevent piston member displacement when said piston member is in a retractive position within the cylinder, the cylinder being free of a return spring member such that the upward action of a normally operative key effectively returns the piston upwardly to a position where the engagement means is engaged.
3 more elements
An actuator apparatus for controllably and selectively actuating the keys of a keyboard-operated apparatus in response to signals from control means comprising:
- a plurality of latching fluid actuators including a latch element and piston means, the piston means including a cylinder closed at one end and a piston member sealably carried within the cylinder and including a piston rod for interacting at one end with the keys of the keyboard, fluid inlet means for providing fluid communication through the cylinder closed end, the latch element having a first member and a second member disposed on opposite sides of the piston rod and a third member interconnecting the first member and the second member, spring means biasing the latch element into engagement with the piston member, the piston member including engagement means for receiving the second member to prevent piston member displacement, and a fluid responsive element acting against the first member and responsive to fluid pressure in communication with the fluid actuator for operating the latch element to disengage the second member from the engagement means, the cylinder being free of a return spring member such that the upward action of a normally operative key effectively returns the piston rod upwardly to a position where the piston rod is retractably latched.
A method of testing the action of a key on a keyboard comprising pressurizing a latch release fluid connector to unlatch a piston rod means;
- pressurizing a drive fluid connection to urge said piston rod means downwardly and the key downwardly;
- measuring a first electrical output from the key;
- depressurizing the fluid connection to allow the key to move upwardly and urge the piston rod upwardly;
- depressurizing a latch release fluid connection to attempt relatching of the piston rod means;
- repressurizing the drive fluid connection to attempt to urge the piston rod means downwardly;
- measuring the second output electrical signal from the key;
- and determining whether there is any difference in the first and second electrical outputs, a difference being indicative of return of the key to its substantially fully raised position and the piston rod means to its latched position.
4 more elements
Dependencies are inferred from the claim text.