Abstract: A piano keyboard apparatus has an action assembly that includes a four bar linkage having four pivotably connected bars including a whippen pivotably connected to a repetition lever. An articulated jack has a lower link pivotably connected to an upper link and the lower link is pivotably connected to the whippen.

Abstract: A combination acoustic mode and electronic mode grand piano is provided including a hammer shank stop rail that intercepts the hammer shank when operating in its electronic mode, so that the hammer cannot complete its normal travel to strike its corresponding string(s) when its key is actuated. The positioning of the hammer shank stop rail is actuated by a user-operated control that, when placed into the "acoustic" mode, raises the hammer shank stop rail to a non-engaged position that does not interfere with the normal movements of the hammer shank. When in the "electronic" mode, the control lowers the hammer shank stop rail into an engaged position where it intercepts the hammer shanks of the piano, thereby preventing each hammer head from striking its respective string(s).

Abstract: An electronic keyboard key apparatus includes a longitudinally extending key pivotally mounted on a supporting base and a simulated hammer assembly including a simulated hammer mounted on a hammer shank that is independently pivotally mounted with respect to the key on the base. A jack means is mounted on the key for striking and pivoting the hammer assembly when the key is struck and a preferably flexible bridle for controlling the hammer assembly connects the hammer assembly to the key. A spring is connected between a back end of the key and the base for quickly returning the key to its at rest position. The bridle may be a flexible strap. The simulated hammer may be a metallic cylinder disposed about a first distal end of the hammer shank. A butt is attached to a second distal end of the shank and the butt has a butt end that is bifurcated to form two hinge lugs that are hinged to a single hinge lug of a lug mount fixedly connected to the base.

Abstract: A combination acoustic mode and electronic mode grand piano is provided including a hammer shank stop rail that intercepts the hammer shank when operating in its electronic mode, so that the hammer cannot complete its normal travel to strike its corresponding string(s) when its key is actuated. The positioning of the hammer shank stop rail is actuated by a user-operated control that, when placed into the "acoustic" mode, raises the hammer shank stop rail to a non-engaged position that does not interfere with the normal movements of the hammer shank. When in the "electronic" mode, the control lowers the hammer shank stop rail into an engaged position where it intercepts the hammer shanks of the piano, thereby preventing each hammer head from striking its respective string(s).

Abstract: An electronic keyboard key apparatus to simulate the feel of escapement includes a longitudinally extending key preferably pivotally mounted on a supporting base, a spring apparatus flexibly disposed between the base and the key for resisting depression of the key with a variable resistive force, a latching apparatus to latch the spring apparatus in connection to the base, and an unlatching apparatus to unlatch the spring apparatus from connection to the base with a predetermined amount of resistive force. The latching apparatus may be a magnetic apparatus disposed between the base and the spring apparatus having one of a magnetic element and a magnetically attracted element fixedly connected to the base and the other fixedly connected to the key.

Abstract: An electronic keyboard musical instrument is provided having optical emitters and detectors both positioned beneath each of the instrument's keys, whereby optical energy is emitted upon the bottom reflective surface of the key and the reflected light is detected. The distance between the optoelectronic sensor and the bottom of the key is detected by the light detector which produces an analog output signal and, by measuring the time between a first and second threshold crossing, the key's velocity can be determined. The two thresholds are preferably chosen to measure a rising voltage as the key is depressed, and the threshold values are preferably chosen at 50% of key travel and 75% of key travel. By use of these thresholds, a relatively clean and useful waveform is available at both threshold crossings, particularly since the mechanical movement of the key has nearly reached its terminal velocity.

Abstract: An improved combination acoustic-mode and electronic-mode piano is provided which includes a hammer shank stop rail that intercepts the hammer shank, when in the electronic mode, so that the hammer cannot complete its normal travel and cannot strike its corresponding string(s) when its piano key is actuated. The hammer shank stop rail is actuated by an intermediate crank that, in turn, is actuated by a pedal dowel attached to one of the pedals of the piano. When operated in the acoustic mode, the stop rail occupies a position that will not interfere with the hammer shank's movements, and when in the electronic mode, the stop rail intercepts the hammer shank so that its associated hammer will not be able to travel all the way into contact with their associated string. A second embodiment operates the stop rail by use of a cable and cam mechanism. A third embodiment uses a hand-actuator to operate the stop rail via a dowel and intermediate crank.

Abstract: Optical components and methods for an I.V. flow detector providing complete coverage of a drip chamber through the use of a single emitter and receiver. The optical components take the light of a single emitter and spread it uniformly across the entire drip chamber. Furthermore, the light is collimated as it passes through the chamber. In addition, the optics collimates the light at some point in its path from the emitter to the drip chamber. Similarly, it collimates the beam of radiation at some point in its path from the drip chamber to the receiver. Further, the optics creates a plane of symmetry for the light path passing through the center of the drip chamber and lies perpendicular to the path of the light. The design specifically takes into account the optical characteristics of the drip chamber itself.

Abstract: A housing for a laptop computer or computer terminal and the computer and terminal themselves in which opening the top causes a curved surface to descend below the computer's rear, bottom surface. This ridge runs across at least half of the bottom of the computer's back and preferably the entire computer. It serves to support the bottom section of the cover, and thus the keyboard, when used on a person's lap at a suitable angle. Specifically, it elevates the rear of the keyboard so that the hands have facile access to all the keys. The curved surface is formed integrally with the edge of the computer cover's upper section. When the top closes, the surface moves to a position where it does not descend below the bottom of the cover in order to provide a neat, portable package. Opening the top causes the surface, or ridge, to occupy the position where it will sit on the person's legs to prop up the keyboard.

Abstract: An adjustable clutch mechanism for fixing the relative position of two objects rotationally coupled relative to each other. The pressure resisting the change of rotational position submits to adjustment to permit facile movement but yet resists change from the selected position. The mechanism finds particular utility for holding a portable computer terminal's cover containing a display at a desired position relative to the base containing the keys. The clutch mechanism itself includes two sets of annular rings held against each other by a nut and bolt pressing against a spring which in turn presses against one of the rings. Tightening the screw applies greater pressure to the rings and prevents the relative rotation. The first set of the rings moves with the cover while the second set of rings has a fixed rotational orientation relative to the base. A tubular shaft, affixed to the base, passes through the center of the rings engaging tabs of the second set.

Abstract: A parallel motion linkage is taught for the sliding keyboard cover of a piano to assure that the sliding keyboard cover, when shifted between its open (key exposing) position and its closed (key covering) position will remain perpendicular to the direction of its motion and will not skew or jam between the sides of the piano case. The structure comprises a pair of bell cranks rotatively mounted to the underside of the sliding keyboard cover near the ends thereof. The bell cranks each have a first short arm, which arms are joined together by a tie rod pivotally connected thereto. The bell cranks each have a long arm to which one end of a connecting rod is pivotally mounted. The free end of each connecting rod is detachably and adjustably affixed to a bracket mounted on its respective side of the piano case.

Abstract: A cymbal stand is taught comprising upper and lower tubular members in adjustable telescoping relationship. A pedal frame is affixed to the bottom end of the lower tubular member. The rearward end of a foot pedal is pivotally connected by a pair of arms to the pedal frame. The forward end of the foot pedal is pivotally attached directly to an actuating rod assembly extending upwardly through the pedal frame and the upper and lower tubular members. The pivotal attachments of the foot pedal arms to the pedal bracket and the forward end of the pedal to the rod assembly are coaxial, so that the pedal is swingable beneath the pedal frame between an operating position to one side of the pedal frame and a stowed position alongside the pedal frame and the lower tubular member on the other side of the pedal frame. The structure is provided with a set of pivotally attached legs terminating in footed free end.