Abstract: A linear actuator includes a stationary stator and an external armature moving with a coil moving within a magnetic structure. A linear bearing including a stationary track fastened to the stator and a moving track fastened to the armature extends on each side of the magnetic structure. In each linear bearing, balls rotate between the stationary and moving tracks with movement of the armature. During the process of manufacturing the linear actuator, the moving track of each linear bearing is loosely mounted to the armature, a pre-load force is applied to the moving track using a tool fastened to the armature, and the moving track is clamped in place so that the pre-load force is subsequently maintained.

Abstract: A dual contact probe tip is provided within a flying probe circuit tester to make separate electrical contacts with a circuit under test at two closely-spaced test points. The tip includes a mounting block having an attachment section attached to a carriage of the tester and a pair of flexible cantilever sections, with a probe pin extending from a distal end of each of these cantilever sections to make contact with the circuit. One electrical path is established through the conductive mounting block and one of the probe pins. The other probe pin is coated with an insulating material except for its point and for a surface to which a wire is soldered, so that the other electrical path is established through this other probe pin and the attached wire. Each probe pin is tapered toward its point, and the probe pins extend from the mounting block at an oblique angle toward one another.

Abstract: A self erecting personal water safety device includes a marker device having a flag portion and a base portion normally in the collapsed state; an erection chamber in the flag portion and a compressible storage chamber in the base portion for storing an actuating fluid and interconnected with the erection chamber for compressing when submerged in water to transfer fluid to the erection chamber and erect the flag portion.

Abstract: An actuator providing Z-direction movement within a positioning system extends between an input stage and an output stage. A nut is mounted to rotate on the input stage in threaded engagement with a screw extending into the nut from the output stage. The nut is driven by a motor also mounted on the input stage. A plate attached to the output stage through a flexible leaf spring slides along the input stage in the Z-direction with movement of the output stage, preventing rotation of the output stage about the axis of the screw. Lateral positioning of the screw results from the threaded engagement of the screw and nut. The leaf spring is formed to provide a lateral pre-load force between the screw and nut.

Abstract: A control unit for a motorized wheelchair for an invalid the control unit having a part engageable with the occupants chin and being movable in a first direction in order to cause movement of the wheelchair in a forwards direction and in a second and third direction to steer the wheelchair either to the left or to the right, an on/off and reverse/forward switch being provided operable by the occupants head.