Abstract: An angle adjusting device for adjusting the relative positions of musical instruments, such as a bass drum and jazz tomtom. The angle adjusting device has two rods for holding the musical instruments separately. Each rod has a head which includes an annular inclined toothed portion. A wing nut mounted on one end of the axle and a lever having a cam surface for abutting against the wall of either one of the heads, through which full engagement, partial engagement and disengagement can be accurately set. Thus, rotation of one head relative to the other to adjust the angle of two rod can be implemented simply by singlehanded actuation of the lever.

Abstract: An impact print head for a matrix printer employs the usual set of wires slidably mounted in the head which are selectively extended from the working end of the head toward a platen by energizing solenoid actuators. However, in lieu of the usual solenoid strikers, return springs therefor and print wire return springs, a single set of unitary ferromagnetic spring arms connected directly to the print wires and positioned opposite the solenoids mounted in a unitary solenoid frame assembly. Also a shunt plate is mounted in the head and positioned on the opposite sides of the spring arms from the solenoids. The shunt disk and frame assembly shape the magnetic flux pattern from each energized solenoid so that a maximum number of flux lines from each solenoid intercept the associated spring arm to attain maximum dynamic print range and efficiency.